Tele-Neuropsychology: From Science to Policy to Practice.

OBJECTIVE: The primary aim of this paper is to accelerate the number of randomized experimental studies of the reliability and validity in-home tele-neuropsychological testing (tele-np-t). METHOD: We conducted a critical review of the tele-neuropsychology literature. We discuss this research in the context of the United States' public and private healthcare payer systems, including the Centers for Medicare & Medicaid Services (CMS) and Current Procedural Terminology (CPT) coding system's telehealth lists, and existing disparities in healthcare access. RESULTS: The number of tele-np publications has been stagnant since the onset of the COVID-19 pandemic. There are less published experimental studies of tele-neuropsychology (tele-np), and particularly in-home tele-np-t, than other tele-np publications. There is strong foundational evidence of the acceptability, feasibility, and reliability of tele-np-t, but relatively few studies of the reliability and validity of in-home tele-np-t using randomization methodology. CONCLUSIONS: More studies of the reliability and validity of in-home tele-np-t using randomization methodology are necessary to support inclusion of tele-np-t codes on the CMS and CPT telehealth lists, and subsequently, the integration and delivery of in-home tele-np-t services across providers and institutions. These actions are needed to maintain equitable reimbursement of in-home tele-np-t services and address the widespread disparities in healthcare access.

Author Correction: Neuroprotective pentapeptide CN-105 improves functional and histological outcomes in a murine model of intracerebral hemorrhage.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Enduring alterations in hippocampal astrocytesynaptic proximity following adolescent alcohol exposure: reversal by gabapentin.

Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years. Despite reports of a wide range of effects of adolescent intermittent ethanol (AIE) exposure on brain and behavior, little is known about the mechanisms that may underlie those effects, and even less about treatments that might reverse them. Recent studies from our laboratory have indicated that AIE produced enduring changes in astrocyte function and synaptic activity in the hippocampal formation, suggesting the possibility of an alteration in astrocyte-neuronal connectivity and function. We utilized astrocyte-specific, membrane restricted viral labeling paired with immunohistochemistry to perform confocal single cell astrocyte imaging, three-dimensional reconstruction, and quantification of astrocyte morphology in hippocampal area CA1 from adult rats after AIE. Additionally, we assessed the colocalization of astrocyte plasma membrane labeling with immunoreactivity for AMPA-(α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) glutamate receptor 1, an AMPA receptor subunit and established neuronal marker of excitatory synapses, as a metric of astrocyte-synapse proximity. AIE significantly reduced the colocalization of the astrocyte plasma membrane with synaptic marker puncta in adulthood. This is striking in that it suggests not only an alteration of the physical association of astrocytes with synapses by AIE, but one that lasts into adulthood - well after the termination of alcohol exposure. Perhaps even more notable, the AIE-induced reduction of astrocyte-synapse interaction was reversed by sub-chronic treatment with the clinically used agent, gabapentin (Neurontin), in adulthood. This suggests that a medication in common clinical use may have the potential to reverse some of the enduring effects of adolescent alcohol exposure on brain function. All animal experiments conducted were approved by the Duke University Institutional Animal Care and Use Committee (Protocol Registry Number A159-18-07) on July 27, 2018.

Behavioral Inefficiency on a Risky Decision-Making Task in Adulthood after Adolescent Intermittent Ethanol Exposure in Rats.

Adolescence is a period of development in neural circuits that are critical for adult functioning. There is a relationship between alcohol exposure and risky decision-making, though the enduring effects of adolescent ethanol exposure on risky decision-making in adulthood have not been fully explored. Studies using positive reinforcement have shown that adolescent intermittent ethanol (AIE) exposure results in higher levels of risky decision-making in adulthood, but the effects of AIE on punishment-mediated decision-making have not been explored. Adolescent rats were exposed to AIE or saline vehicle across a 16-day period, and then allowed to mature into adulthood. They were then trained to lever press for food reward and were assessed for risky decision-making by pairing increased levels of food reward with the probability of footshock punishment. AIE did not alter punishment-mediated risky decision-making. However, it did result in a significant increase in the delay to lever pressing. This finding is consistent with previous reports, using other behavioral tasks, which show decreased behavioral efficiency in adulthood after AIE. These findings indicate that AIE increases behavioral inefficiency, but not punishment-mediated risk-taking, in adulthood. Thus they contribute to a more nuanced understanding of the long-term effects of AIE on adult behavior.

A blood-based biomarker panel to risk-stratify mild traumatic brain injury.

Mild traumatic brain injury (TBI) accounts for the vast majority of the nearly two million brain injuries suffered in the United States each year. Mild TBI is commonly classified as complicated (radiographic evidence of intracranial injury) or uncomplicated (radiographically negative). Such a distinction is important because it helps to determine the need for further neuroimaging, potential admission, or neurosurgical intervention. Unfortunately, imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) are costly and not without some risk. The purpose of this study was to screen 87 serum biomarkers to identify a select panel of biomarkers that would predict the presence of intracranial injury as determined by initial brain CT. Serum was collected from 110 patients who sustained a mild TBI within 24 hours of blood draw. Two models were created. In the broad inclusive model, 72kDa type IV collagenase (MMP-2), C-reactive protein (CRP), creatine kinase B type (CKBB), fatty acid binding protein-heart (hFABP), granulocyte-macrophage colony-stimulating factor (GM-CSF) and malondialdehyde modified low density lipoprotein (MDA-LDL) significantly predicted injury visualized on CT, yielding an overall c-statistic of 0.975 and a negative predictive value (NPV) of 98.6. In the parsimonious model, MMP-2, CRP, and CKBB type significantly predicted injury visualized on CT, yielding an overall c-statistic of 0.964 and a negative predictive value (NPV) of 97.2. These results suggest that a serum based biomarker panel can accurately differentiate patients with complicated mild TBI from those with uncomplicated mild TBI. Such a panel could be useful to guide early triage decisions, including the need for further evaluation or admission, especially in those environments in which resources are limited.

Neuroprotective pentapeptide CN-105 improves functional and histological outcomes in a murine model of intracerebral hemorrhage.

Presently, no pharmacological treatments have been demonstrated to improve long-term functional outcomes following intracerebral hemorrhage (ICH). Clinical evidence associates apolipoprotein E (apoE) genotype with ICH incidence and outcome. While apoE modifies neuroinflammatory responses through its adaptive role in glial downregulation, intact apoE holoprotein is too large to cross the blood-brain barrier (BBB). Therefore, we developed a 5-amino acid peptide - CN-105 - that mimics the polar face of the apoE helical domain involved in receptor interactions. In the current study, we investigated the therapeutic potential of CN-105 in a mouse model of ICH. Three doses of CN-105 (0.05 mg/kg) was administered by tail vein injection within 24 hours after ICH induction. Functional assessment showed durable improvement in vestibulomotor performance after CN-105 treatment, as quantified by increased Rotarod latencies on Days 1-5 post-ICH, and long-term improvement in neurocognitive performance, as quantified by reduced Morris water maze latencies on Days 29-32 post-ICH. Further, brain water content was significantly reduced, neuroinflammation was decreased and hippocampal CA3 neuronal survival was increased, although hemorrhage volume was not affected by CN-105. We concluded, therefore, that pentapeptide CN-105 improved short- and long-term neurobehavioral outcomes in a murine model of ICH, suggesting therapeutic potential for patients with acute ICH.

Opposing effects of traumatic brain injury on excitatory synaptic function in the lateral amygdala in the absence and presence of preinjury stress.

Traumatic brain injury (TBI) is a leading cause of death and disability among young adults and is highly prevalent among recently deployed military personnel. Survivors of TBI often experience cognitive and emotional deficits, suggesting that long-term effects of injury may disrupt neuronal function in critical brain regions, including the amygdala, which is involved in emotion and fear memory. Amygdala hyperexcitability has been reported in both TBI and posttraumatic stress disorder patients, yet little is known regarding the effects of combined stress and TBI on amygdala structure and function at the neuronal level. The present study seeks to determine how the long-term effects of preinjury foot-shock stress and TBI interact to influence synaptic plasticity in the lateral amygdala (LA) of adult male C57BL/6J mice by using whole-cell patch clamp electrophysiology 2-3 months postinjury. In the absence of stress, TBI resulted in a significant increase in membrane excitability and spontaneous excitatory postsynaptic currents (sEPSCs) in LA pyramidal-like neurons. Foot-shock stress in the absence of TBI also resulted in increased sEPSC activity. In contrast, when preinjury stress and TBI occurred in combination, sEPSC activity was significantly decreased compared with either condition alone. There were no significant differences in inhibitory activity or total dendritic length among any of the treatment groups. These results demonstrate that stress and TBI may be contributing to amygdala hyperexcitability via different mechanisms and that these pathways may counterbalance each other with respect to long-term pathophysiology in the LA.

Adolescent Intermittent Alcohol Exposure: Deficits in Object Recognition Memory and Forebrain Cholinergic Markers.

The long-term effects of intermittent ethanol exposure during adolescence (AIE) are of intensive interest and investigation. The effects of AIE on learning and memory and the neural functions that drive them are of particular interest as clinical findings suggest enduring deficits in those cognitive domains in humans after ethanol abuse during adolescence. Although studies of such deficits after AIE hold much promise for identifying mechanisms and therapeutic interventions, the findings are sparse and inconclusive. The present results identify a specific deficit in memory function after AIE and establish a possible neural mechanism of that deficit that may be of translational significance. Male rats (starting at PND-30) received exposure to AIE (5g/kg, i.g.) or vehicle and were allowed to mature into adulthood. At PND-71, one group of animals was assessed using the spatial-temporal object recognition (stOR) test to evaluate memory function. A separate group of animals was used to assess the density of cholinergic neurons in forebrain areas Ch1-4 using immunohistochemistry. AIE exposed animals manifested deficits in the temporal component of the stOR task relative to controls, and a significant decrease in the number of ChAT labeled neurons in forebrain areas Ch1-4. These findings add to the growing literature indicating long-lasting neural and behavioral effects of AIE that persist into adulthood and indicate that memory-related deficits after AIE depend upon the tasks employed, and possibly their degree of complexity. Finally, the parallel finding of diminished cholinergic neuron density suggests a possible mechanism underlying the effects of AIE on memory and hippocampal function as well as possible therapeutic or preventive strategies for AIE.

Adolescent intermittent alcohol exposure: persistence of structural and functional hippocampal abnormalities into adulthood.

BACKGROUND: Human adolescence is a crucial stage of neurological development during which ethanol (EtOH) consumption is often at its highest. Alcohol abuse during adolescence may render individuals at heightened risk for subsequent alcohol abuse disorders, cognitive dysfunction, or other neurological impairments by irreversibly altering long-term brain function. To test this possibility, we modeled adolescent alcohol abuse (i.e., intermittent EtOH exposure during adolescence [AIE]) in rats to determine whether adolescent exposure to alcohol leads to long-term structural and functional changes that are manifested in adult neuronal circuitry. METHODS: We specifically focused on hippocampal area CA1, a brain region associated with learning and memory. Using electrophysiological, immunohistochemical, and neuroanatomical approaches, we measured post-AIE changes in synaptic plasticity, dendritic spine morphology, and synaptic structure in adulthood. RESULTS: We found that AIE-pretreated adult rats manifest robust long-term potentiation, induced at stimulus intensities lower than those required in controls, suggesting a state of enhanced synaptic plasticity. Moreover, AIE resulted in an increased number of dendritic spines with characteristics typical of immaturity. Immunohistochemistry-based analysis of synaptic structures indicated a significant decrease in the number of co-localized pre- and postsynaptic puncta. This decrease is driven by an overall decrease in 2 postsynaptic density proteins, PSD-95 and SAP102. CONCLUSIONS: Taken together, these findings reveal that repeated alcohol exposure during adolescence results in enduring structural and functional abnormalities in the hippocampus. These synaptic changes in the hippocampal circuits may help to explain learning-related behavioral changes in adult animals preexposed to AIE.

Adolescent alcohol exposure alters GABAA receptor subunit expression in adult hippocampus.

BACKGROUND: The long-term consequences of adolescent alcohol abuse that persist into adulthood are poorly understood and have not been widely investigated. We have shown that intermittent exposure to alcohol during adolescence decreased the amplitude of GABAA receptor (GABAA R)-mediated tonic currents in hippocampal dentate granule cells in adulthood. The aim of this study was to investigate the enduring effects of chronic intermittent alcohol exposure during adolescence or adulthood on the expression of hippocampal GABAA Rs. METHODS: We used a previously characterized tissue fractionation method to isolate detergent resistant membranes and soluble fractions, followed by Western blots to measure GABAA R protein expression. We also measured mRNA levels of GABAA R subunits using quantitative real-time polymerase chain reaction. RESULTS: Although the protein levels of α1-, α4-, and δ-GABAA R subunits remained stable between postnatal day (PD) 30 (early adolescence) and PD71 (adulthood), the α5-GABAA R subunit was reduced across that period. In rats that were subjected to adolescent intermittent ethanol (AIE) exposure between PD30 and PD46, there was a significant reduction in the protein levels of the δ-GABAA R, in the absence of any changes in mRNA levels, at 48 hours and 26 days after the last ethanol (EtOH) exposure. Protein levels of the α4-GABAA R subunit were significantly reduced, but mRNA levels were increased, 26 days (but not 48 hours) after the last AIE exposure. Protein levels of α5-GABAA R were not changed by AIE, but mRNA levels were reduced at 48 hours but normalized 26 days after AIE. In contrast to the effects of AIE, chronic intermittent ethanol (CIE) exposure during adulthood had no effect on expression of any of the GABAA R subunits examined. CONCLUSIONS: AIE produced both short- and long-term alterations of GABAA R subunits mRNA and protein expression in the hippocampus, whereas CIE produced no long-lasting effects on those measures. The observed reduction of protein levels of the δ-GABAA R, specifically, is consistent with previously reported altered hippocampal GABAA R-mediated electrophysiological responses after AIE. The absence of effects of CIE underscores the emerging view of adolescence as a time of distinctive vulnerability to the enduring effects of repeated EtOH exposure.

Effect of sub-chronic intermittent ethanol exposure on spatial learning and ethanol sensitivity in adolescent and adult rats.

It has become clear that adolescence is a period of distinct responsiveness to the acute effects of ethanol on learning and other cognitive functions. However, the effects of repeated intermittent ethanol exposure during adolescence on learning and cognition are less well studied, and other effects of repeated ethanol exposure such as withdrawal and chronic tolerance complicate such experiments. Moreover, few studies have compared the effects of repeated ethanol exposure during adolescence and adulthood, and they have yielded mixed outcomes that may be related to methodological differences and/or secondary effects of ethanol on behavioral performance. One emerging question is whether relatively brief intermittent ethanol exposure (i.e., sub-chronic exposure) during adolescence or adulthood might alter learning at a time after exposure when chronic tolerance would be expected, and whether tolerance to the cognitive effects of ethanol might influence the effect of ethanol on learning at that time. To address this, male adolescent and adult rats were pre-treated with sub-chronic daily ethanol (five doses [4.0 g/kg, i.p.] or saline at 24-h intervals, across 5 days). Two days after the last pre-exposure, spatial learning was assessed on 4 consecutive days using the Morris water maze. Half of the animals from each treatment cell received ethanol (2.0 g/kg, i.p.) 30 min prior to each testing session and half of the animals received saline. Ethanol pre-exposure altered water maze performance in adult animals but not in adolescents, and acute ethanol exposure impaired learning in animals of both ages independent of pre-exposure condition. There was no evidence of cognitive tolerance in animals of either age group. These results indicate that a relatively short period of intermittent ethanol exposure during adulthood, but not adolescence, promotes thigmotaxis in the water maze shortly after pre-exposure but does not induce cognitive tolerance to the effects of ethanol in either age group.

Regional-specific effects of ovarian hormone loss on synaptic plasticity in adult human APOE targeted replacement mice.

The human apolipoprotein ε4 allele (APOE4) has been implicated as one of the strongest genetic risk factors associated with Alzheimer's disease (AD) and in influencing normal cognitive functioning. Previous studies have demonstrated that mice expressing human apoE4 display deficits in behavioral and neurophysiological outcomes compared to those with apoE3. Ovarian hormones have also been shown to be important in modulating synaptic processes underlying cognitive function, yet little is known about how their effects are influenced by apoE. In the current study, female adult human APOE targeted replacement (TR) mice were utilized to examine the effects of human APOE genotype and long-term ovarian hormone loss on synaptic plasticity in limbic regions by measuring dendritic spine density and electrophysiological function. No significant genotype differences were observed on any outcomes within intact mice. However, there was a significant main effect of genotype on total spine density in apical dendrites in the hippocampus, with post-hoc t-tests revealing a significant reduction in spine density in apoE3 ovariectomized (OVX) mice compared to sham operated mice. There was also a significant main effect of OVX on the magnitude of LTP, with post-hoc t-tests revealing a decrease in apoE3 OVX mice relative to sham. In contrast, apoE4 OVX mice showed increased synaptic activity relative to sham. In the lateral amygdala, there was a significant increase in total spine density in apoE4 OVX mice relative to sham. This increase in spine density was consistent with a significant increase in spontaneous excitatory activity in apoE4 OVX mice. These findings suggest that ovarian hormones differentially modulate synaptic integrity in an apoE-dependent manner within brain regions that are susceptible to neurophysiological dysfunction associated with AD.

Altered neurotransmission in the lateral amygdala in aged human apoE4 targeted replacement mice.

The human APOE4 allele is associated with an early age of onset and increased risk of Alzheimer's disease (AD). Apolipoprotein E is secreted as part of a high-density lipoprotein-like particle by glial cells in the brain for the primary purpose of transport of lipophilic compounds involved in the maintenance of synapses. Previous studies examining synaptic integrity in the amygdala of human apoE targeted replacement (TR) mice showed a decrease in spontaneous excitatory synaptic activity, dendritic arbor, and spine density associated with apoE4 compared with apoE3 and apoE2 in adult male mice. In the present study, we assessed how APOE genotype affects synaptic integrity of amygdala neurons by comparing electrophysiological and morphometric properties in human apoE3, E4, and E2/4 TR mice at the age of 18-20 months. In contrast to adult mice, we found that aged apoE4 TR mice exhibited the highest level of excitatory synaptic activity compared with other cohorts. Additionally, apoE4 mice had significantly greater spontaneous inhibitory activity than all other cohorts. Taken together, there was a significant interaction between genotypes when comparing inhibition relative to excitation; there was a simple main effect of frequency type with an imbalance toward inhibition in apoE4 mice but not in apoE3 or apoE2/4 mice. These results suggest that apoE isoforms differentially influence synaptic transmission throughout the life span, where aging coupled with apoE4 expression, results in an imbalance in maintaining integrity of synaptic transmission.

Effects of acute or chronic ethanol exposure during adolescence on behavioral inhibition and efficiency in a modified water maze task.

Ethanol is well known to adversely affect frontal executive functioning, which continues to develop throughout adolescence and into young adulthood. This is also a developmental window in which ethanol is misused by a significant number of adolescents. We examined the effects of acute and chronic ethanol exposure during adolescence on behavioral inhibition and efficiency using a modified water maze task. During acquisition, rats were trained to find a stable visible platform onto which they could escape. During the test phase, the stable platform was converted to a visible floating platform (providing no escape) and a new hidden platform was added in the opposite quadrant. The hidden platform was the only means of escape during the test phase. In experiment 1, adolescent animals received ethanol (1.0 g/kg) 30 min before each session during the test phase. In experiment 2, adolescent animals received chronic intermittent ethanol (5.0 g/kg) for 16 days (PND30 To PND46) prior to any training in the maze. At PND72, training was initiated in the same modified water maze task. Results from experiment 1 indicated that acute ethanol promoted behavioral disinhibition and inefficiency. Experiment 2 showed that chronic intermittent ethanol during adolescence appeared to have no lasting effect on behavioral disinhibition or new spatial learning during adulthood. However, chronic ethanol did promote behavioral inefficiency. In summary, results indicate that ethanol-induced promotion of perseverative behavior may contribute to the many adverse behavioral sequelae of alcohol intoxication in adolescents and young adults. Moreover, the long-term effect of adolescent chronic ethanol exposure on behavioral efficiency is similar to that observed after chronic exposure in humans.

Long-term modulation of A-type K(+) conductances in hippocampal CA1 interneurons in rats after chronic intermittent ethanol exposure during adolescence or adulthood.

BACKGROUND: Chronic alcohol use, especially exposure to alcohol during adolescence or young adulthood, is closely associated with cognitive deficits that may persist into adulthood. Therefore, it is essential to identify possible neuronal mechanisms underlying the observed deficits in learning and memory. Hippocampal interneurons play a pivotal role in regulating hippocampus-dependent learning and memory by exerting strong inhibition on excitatory pyramidal cells. The function of these interneurons is regulated not only by synaptic inputs from other types of neurons but is also precisely governed by their own intrinsic membrane ionic conductances. The voltage-gated A-type potassium current (IA ) regulates the intrinsic membrane properties of neurons, and disruption of IA is responsible for many neuropathological processes including learning and memory deficits. Thus, it represents a previously unexplored cellular mechanism whereby chronic ethanol (EtOH) may alter hippocampal memory-related functioning. METHODS: Using whole-cell electrophysiological recording methods, we investigated the enduring effects of chronic intermittent ethanol (CIE) exposure during adolescence or adulthood on IA in rat CA1 interneurons. RESULTS: We found that the mean peak amplitude of IA was significantly reduced after CIE in either adolescence or adulthood, but IA density was attenuated after CIE in adolescence but not after CIE in adulthood. In addition, the voltage-dependent steady-state activation and inactivation of IA were altered in interneurons after CIE. CONCLUSIONS: These findings suggest that CIE can cause long-term changes in IA channels in interneurons and thus may alter their inhibitory influences on memory-related local hippocampal circuits, which could be, in turn, responsible for learning and memory impairments observed after chronic EtOH exposure.

Long-term effects of chronic intermittent ethanol exposure in adolescent and adult rats: radial-arm maze performance and operant food reinforced responding.

BACKGROUND: Adolescence is not only a critical period of late-stage neurological development in humans, but is also a period in which ethanol consumption is often at its highest. Given the prevalence of ethanol use during this vulnerable developmental period we assessed the long-term effects of chronic intermittent ethanol (CIE) exposure during adolescence, compared to adulthood, on performance in the radial-arm maze (RAM) and operant food-reinforced responding in male rats. METHODOLOGY/PRINCIPAL FINDINGS: Male Sprague Dawley rats were exposed to CIE (or saline) and then allowed to recover. Animals were then trained in either the RAM task or an operant task using fixed- and progressive- ratio schedules. After baseline testing was completed all animals received an acute ethanol challenge while blood ethanol levels (BECs) were monitored in a subset of animals. CIE exposure during adolescence, but not adulthood decreased the amount of time that animals spent in the open portions of the RAM arms (reminiscent of deficits in risk-reward integration) and rendered animals more susceptible to the acute effects of an ethanol challenge on working memory tasks. The operant food reinforced task showed that these effects were not due to altered food motivation or to differential sensitivity to the nonspecific performance-disrupting effects of ethanol. However, CIE pre-treated animals had lower BEC levels than controls during the acute ethanol challenges indicating persistent pharmacokinetic tolerance to ethanol after the CIE treatment. There was little evidence of enduring effects of CIE alone on traditional measures of spatial and working memory. CONCLUSIONS/SIGNIFICANCE: These effects indicate that adolescence is a time of selective vulnerability to the long-term effects of repeated ethanol exposure on neurobehavioral function and acute ethanol sensitivity. The positive and negative findings reported here help to further define the nature and extent of the impairments observed after adolescent CIE and provide direction for future research.

Binge-pattern ethanol exposure during adolescence, but not adulthood, causes persistent changes in GABAA receptor-mediated tonic inhibition in dentate granule cells.

BACKGROUND: In recent years, it has become clear that acute ethanol (EtOH) affects various neurobiological and behavioral functions differently in adolescent animals than in adults. However, less is known about the long-term neural consequences of chronic EtOH exposure during adolescence, and most importantly whether adolescence represents a developmental period of enhanced vulnerability to such effects. METHODS: We made whole-cell recordings of GABAA receptor-mediated tonic inhibitory currents from dentate gyrus granule cells (DGGCs) in hippocampal slices from adult rats that had been treated with chronic intermittent ethanol (CIE) or saline during adolescence, young adulthood, or adulthood. RESULTS: CIE reduced baseline tonic current amplitude in DGGCs from animals pretreated with EtOH during adolescence, but not in GCs from those pretreated with EtOH during young adulthood or adulthood. Similarly, the enhancement of tonic currents by acute EtOH exposure ex vivo was increased in GCs from animals pretreated with EtOH during adolescence, but not in those from animals pretreated during either of the other 2 developmental periods. CONCLUSIONS: These findings underscore our recent report that CIE during adolescence results in enduring alterations in tonic current and its acute EtOH sensitivity and establish that adolescence is a developmental period during which the hippocampal formation is distinctively vulnerable to long-term alteration by chronic EtOH exposure.

ApolipoproteinE mimetic peptides improve outcome after focal ischemia.

Growing clinical evidence implicates isoform-specific effects of apolipoprotein E (apoE) in reducing neuroinflammation and mediating adaptive responses following ischemic and traumatic brain injury. However, the intact apoE holoprotein does not cross the blood-brain barrier and thus has limited therapeutic potential. We have created a small peptide, COG1410 (acetyl-AS-Aib-LRKL-Aib-KRLL-amide), derived from the apoE receptor-binding region. COG1410 retains the anti-inflammatory and neuroprotective biological properties of the intact holoprotein and penetrates the blood-brain barrier. In the current study, we utilized a murine model of transient focal cerebral ischemia and reperfusion to demonstrate that intravenous (IV) administration of COG1410 reduces infarct volume and radiographic progression of infarct, and improves functional outcome as assessed by rotarod when delivered up to 4h after ischemia onset.

Effects of ethanol, Δ(9)-tetrahydrocannabinol, or their combination on object recognition memory and object preference in adolescent and adult male rats.

Recent advances have been made in our understanding of the deleterious effects of both ethanol and THC on adolescent behavior and brain development. However, very little is known about the combined effects of EtOH+THC during adolescence, a time in which these drugs are often used together. The purpose of this experiment was to: (1) determine whether EtOH and/or THC induced greater working memory impairment in adolescent than adult male rats using the novel object recognition (NOR) task and (2) determine whether the EtOH+THC combination would produce a more potent additive effect in adolescents than adults when compared to these drugs alone. NOR was performed with a 24h delay under each of the four drug conditions: vehicle; 1.5g/kg ethanol; 1.0mg/kg THC; and 1.5g/kg EtOH+1.0mg/kg THC, at 72h intervals. The results show that there was an age effect on working memory in NOR after the EtOH+THC challenge. Specifically, adolescent animals showed a preference for the familiar object whereas adults showed no preference for the novel or familiar object, the latter being characteristic of a classic working memory deficit. These effects were not dependent on changes in exploration across session, global activity across drug condition, or total object exploration. These novel findings clearly indicate that further understanding of this age-drug interaction is crucial to elucidating the influence that adolescent EtOH+THC use may have on repeated drug use and abuse later in life.