Mating and Memory : Can Mating Cues Enhance Cognitive Performance?

The literature on sexual selection and the social brain hypothesis suggest that human cognition and communication evolved, in part, for the purpose of displaying desirable cognitive abilities to potential mates. An evolutionary approach to social cognition implies that proximate mating motives may lead people to display desirable mental traits. In signaling such traits, one can increase the likelihood of attracting a potential mate. Two experiments demonstrated that exposure to mating cues-highly attractive opposite-sex faces-led people to display enhancements in declarative memory-a process underlying a variety of abilities such as resource acquisition, intelligence, and creativity. Experiment 1 showed that men (but not women) displayed enhanced memory for details of a story that was presented during exposure to highly attractive opposite-sex faces. Experiment 2 demonstrated that heightened displays of declarative memory reflect an enhancement in retrieval rather than in encoding. Findings contribute to the literatures on human mating and cognitive performance and provide novel insight into links between social processes and basic cognition.

The selective phosphodiesterase 9 (PDE9) inhibitor PF-04447943 (6-[(3S,4S)-4-methyl-1-(pyrimidin-2-ylmethyl)pyrrolidin-3-yl]-1-(tetrahydro-2H-pyran-4-yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one) enhances synaptic plasticity and cognitive function in rodents.

Inhibition of phosphodiesterase 9 (PDE9) has been reported to enhance rodent cognitive function and may represent a potential novel approach to improving cognitive dysfunction in Alzheimer's disease. PF-04447943, (6-[(3S,4S)-4-methyl-1-(pyrimidin-2-ylmethyl)pyrrolidin-3-yl]-1-(tetrahydro-2H-pyran-4-yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one), a recently described PDE9 inhibitor, was found to have high affinity (Ki of 2.8, 4.5 and 18 nM) for human, rhesus and rat recombinant PDE9 respectively and high selectivity for PDE9 versus PDEs1-8 and 10-11. PF-04447943 significantly increased neurite outgrowth and synapse formation (as indicated by increased synapsin 1 expression) in cultured hippocampal neurons at low (30-100 nM) but not high (300-1000 nM) concentrations. PF-04447943 significantly facilitated hippocampal slice LTP evoked by a weak tetanic stimulus at a concentration of 100 nM but failed to affect response to the weak tetanus at either 30 or 300 nM, or the LTP produced by a theta burst stimulus. Systemic administration of PF-04447943 (1-30 mg/kg p.o.) dose-dependently increased cGMP in the cerebrospinal fluid 30 min after administration indicating target engagement in the CNS of rats. PF-04447943 (1-3 mg/kg p.o.) significantly improved cognitive performance in three rodent cognition assays (mouse Y maze spatial recognition memory model of natural forgetting, mouse social recognition memory model of natural forgetting and rat novel object recognition with a scopolamine deficit). When administered at a dose of 3 mg/kg p.o., which improved performance in novel object recognition, PF-04447943 significantly increased phosphorylated but not total GluR1 expression in rat hippocampal membranes. Collectively these data indicate that PF-04447943 is a potent, selective brain penetrant PDE9 inhibitor that increased indicators of hippocampal synaptic plasticity and improved cognitive function in a variety of cognition models in both rats and mice. Results with PF-04447943 are consistent with previously published findings using a structurally diverse PDE9 inhibitor, BAY73-6199, and further support the suggestion that PDE9 inhibition may represent a novel approach to the palliative remediation of cognitive dysfunction.

Regional differences in neurovascular coupling in rat brain as determined by fMRI and electrophysiology.

Increases in neuronal activity induce local increases in cerebral perfusion. However, our understanding of the processes underlying this neurovascular coupling remains incomplete and, particularly, how these vary across the brain. Recent work supports an important role for astrocytes in neurovascular coupling, in large part via activation of their metabotropic glutamate receptors (mGluR). Here, using a combination of functional magnetic resonance imaging (fMRI) and electrophysiology we demonstrate regional heterogeneity in the mechanisms underlying neurovascular coupling. Direct electrical stimulation of the rat hindpaw sensorimotor cortex induces blood oxygenation level dependent (BOLD) and cerebral blood volume (CBV) fMRI responses in several anatomically distinct cortical and subcortical structures. Following intraperitoneal administration of the type 5 mGluR antagonist, MPEP, both BOLD and CBV responses to cortical stimulation were significantly reduced, whilst the local field potential (LFP) responses remained largely constant. Spatially, the degree of reduction in fMRI responses varied between cortical and subcortical regions (primary cortex approximately 18% vs. striatum approximately 66%), and also between primary and secondary cortical areas ( approximately 18% vs. approximately 55%). Similarly, greater decreases in response amplitude were seen in the contralateral secondary cortex ( approximately 91%) and ipsilateral striatum (approximately 70%), compared to the primary cortex (approximately 44%). Following MPEP, a negative component of the BOLD and CBV responses became more apparent, suggesting that different mechanisms mediate vasodilatory and vasoconstrictory responses. Interestingly, under baseline conditions the quantitative relationship between fMRI and LFP responses in cortical and subcortical regions was markedly different. Our data indicate that coupling between neuronal and fMRI responses is neither empirically nor mechanistically consistent across the brain.

Nitrous oxide and isoflurane are synergistic with respect to amplitude and latency effects on sensory evoked potentials.

OBJECTIVE: Combinations of anesthetic agents are frequently employed to produce the desired clinical effect. No systematic study has been conducted on the effect of the combination of nitrous oxide with a potent inhalational agent such as isoflurane on sensory evoked responses. METHODS: Median nerve somatosensory evoked responses from the cervical and cortical regions (SSEP), auditory brainstem responses (ABR) and flash visual evoked responses (VEP) were tested in baboons. The latency and amplitude of the major response peaks were recorded at five proportionate mixtures of isoflurane (I) and nitrous oxide (N(2)O) (0.8% I only, 0.6% I/20% N(2)O, 0.4% I/40% N(2)O, 0.2% I/60% N(2)O, and 79% N(2)O only). A similar set of experiments were also conducted with 0.8% isoflurane and 0.6% halothane. All data were normalized to 0.8% isoflurane only and Dunnett's method of analysis used to determine which mixtures deviated from the reference values with 0.8% isoflurane. RESULTS: Several combinations of isoflurane with nitrous oxide produced increases in latency (ABR: wave V, VEP, SSEP cervical and cortical) and decreases in amplitude (ABR: amplitude ratio V/I, VEP, cortical SSEP) from that expected if the effects were additive. No deviations were observed with combinations of isoflurane and halothane. CONCLUSIONS: These studies are consistent with drug synergy when isoflurane is mixed with nitrous oxide. This suggests that if these agents are considered for anesthesia when sensory evoked responses are to be monitored that the combination of these agents may produce more amplitude and latency changes than expected from a proportionate mixture of the individual agents.

Measurements of common iliac arterial blood flow in anurans using Doppler ultrasound.

Color Doppler ultrasonography was used to determine time-average mean velocity and cross-sectional area of the common iliac artery in bullfrogs (Rana catesbeiana) and marine toads (Bufo marinus). Volumetric blood flow and weight-adjusted blood flow measurements were calculated from this data. Volumetric flow rates of frogs (31.8 ml/min) and toads (23.6 ml/min) did not differ statistically. However, when flow rates were adjusted for body mass, toads displayed a significantly greater flow rate of 238.1 ml/min/kg compared to 114.4 ml/min/kg for frogs.

Use of niacin in the prevention and management of hyperlipidemia.

Niacin is an inexpensive drug useful in treating various forms of hyperlipidemia. Cardiac doses of niacin are effective in lowering serum triglyceride, low density lipoprotein, and lipoprotein-a levels and in elevating high density lipoprotein levels. Adverse reactions to niacin are varied and dose-dependent and range from annoying cutaneous flushing to hepatic toxicity. Patients advised to use the drug should be carefully screened and monitored. This paper reviews the pathologic and pharmacologic basis for niacin as an antilipemic agent. The biochemical and physiologic effects of the drug and its mechanisms of action are discussed. Emphasis is placed on the importance of aggressive management of serum lipids and the therapeutic uses of niacin. The use of niacin in primary and secondary prevention of heart disease is stressed. A patient education guide is included.

Teaching the use of walkers and canes.

Home care and hospice nurses frequently encounter patients who use assistive devices to safely remain mobile in their homes. Incorrectly used, these devices may contribute to falls. This article provides a review on the use and teaching of these devices to patients and caregivers. A physical therapist, occupational therapist, or rehabilitation nurse should be consulted for any questions about applying the guidelines in this article to patients.

Increased spinal monoamine concentrations after chronic thoracic dorsal rhizotomy in goats.

In goats, bilateral thoracic dorsal rhizotomy (TDR) causes severe ventilatory failure during exercise, followed by progressive functional recovery. We investigated spinal neurochemical changes associated with TDR and/or functional recovery by measuring spinal concentrations of the monoamines serotonin (5-HT), norepinephrine, and dopamine via HPLC. Changes in 5-HT and calcitonin gene-related peptide were visualized with immunohistochemistry. Goat spinal cords were compared 4-15 mo after TDR from T(2) to T(12) (n = 7) with sham-operated (n = 4) or unoperated controls (n = 4). TDR increased the concentration of cervical 5-HT (C(5)-C(6); 122% change), caudal thoracic norepinephrine (T(7)-T(11); 53% change), and rostral thoracic dopamine (T(3)-T(6); 234% change). TDR increased 5-HT-immunoreactive terminal density (dorsal and ventral horns) and nearly eliminated calcitonin gene-related peptide immunoreactivity in the superficial laminae of the dorsal horn in rostral thoracic segments; both effects became less pronounced in caudal thoracic segments. Thus TDR elevates monoamine concentrations in discrete spinal regions, including possible compensatory changes in descending serotonergic inputs to spinal segments not directly affected by TDR (i.e., cervical) but associated with functionally related motor nuclei (i.e., phrenic nucleus).

Thoracic surgery training at the University of Michigan.

The process of thoracic surgery resident education is and always has been taken very seriously at the University of Michigan, where it is regarded as a key mission of the faculty. More attention is paid to the details of providing a supportive educational environment using established principles of education, curriculum planning, evaluation, and feedback. Resident education is the order of business today and, although challenged by the demands of managed care and cost containment, it remains among the most important priorities at the University of Michigan.

The antilipidemic effects of plain and extended-release niacin.

The extensive antihyperlipidemic effects of niacin are well known. Cardiac doses of niacin are effective in lowering low density lipoprotein, triglyceride, and lipoprotein(a) levels and in elevating high density lipoprotein levels. Adverse reactions to niacin range from annoying cutaneous flushing to hepatic toxicity. A new extended-release form of niacin (Niaspan) has been found to have relatively mild hepatic effects. Nighttime dosing of Niaspan appears to attenuate cutaneous flushing. Regardless of the form of drug prescribed, patients advised to use niacin should be carefully screened and monitored. Adverse effects of niacin are emphasized because of their particular importance in the provision of primary care. The dosing schedules for both plain niacin and extended-release niacin are discussed. (c) 2000 by CHF, Inc.

Assessing peripheral arterial disorders in the home: a multidisciplinary clinical guide.

Patients with peripheral vascular diseases (PVD) have venous problems, arterial problems, or both. Although several home care clinical guidelines exist for PVD, the multidisciplinary clinical guidelines for clients with peripheral arterial diseases outlined in this article present new material for nurses and agencies who are interested in developing clinical paths for these challenging patients.