Short term olfactory memory and olfactory function after inhalation anesthetic agents: a randomized clinical trial / Memória olfativa de curta duração e função olfativa após anestésicos inalatórios: estudo clínico randomizado

Abstract Background and objectives: This clinical trial aimed to evaluate the effects of two different inhalation anesthetic agents on postoperative olfactory memory and olfactory function in patients who underwent micro laryngeal surgery. Methods: This randomized prospective controlled study consisted of 102 consecutive patients with a voice disorder. The patients underwent micro laryngeal surgery for voice disorders under general anesthesia. Patients who did not meet inclusion criteria and/or declined to participate (n = 34) were excluded from the study. Patients were divided into two groups. Four patients from Group 1 and four patients from Group 2 were lost to follow-up. Group 1 (n = 30) received sevoflurane, and Group 2 (n = 30) received desflurane during anesthesia. We compared the results by performing the pre-op and post-op Connecticut Chemosensory Clinical Research Center Olfactory test. Results: Thirty-three patients (55%) were male and 27 (45%) were female. The mean age was 48.18 ± 13.88 years (range: 19‒70 years). Preoperative and postoperative olfactory functions did not show a significant difference within the groups postoperatively (p > 0.05). Preoperative and postoperative olfactory memory showed a significant decrease 3 hours after the surgery (p < 0.05). Conclusions: Olfactory functions and memory were not affected by desflurane in the early postoperative period. Although sevoflurane did not affect olfactory functions, it had a temporary negative effect on olfactory memory in the early postoperative period.

Resumo Introdução e objetivos: O estudo avaliou o efeito pós-operatório de dois agentes anestésicos inalatórios distintos na memória olfativa de curta duração e na função olfativa em pacientes submetidos à microcirurgia de laringe. Método: O estudo prospectivo controlado randomizado avaliou, consecutivamente, 102 pacientes com alteração vocal submetidos à microcirurgia de laringe sob anestesia geral. Trinta e quatro pacientes não obedeceram aos critérios de inclusão e/ou não aceitaram participar do estudo e foram excluídos. Os pacientes foram divididos em dois grupos. Quatro pacientes do Grupo 1 e quatro do Grupo 2 foram perdidos durante o seguimento. O Grupo 1 (n = 30) recebeu sevoflurano durante a anestesia e o Grupo 2 (n = 30), desflurano. Comparamos resultados pré e pós-operatórios de memória olfativa e funções olfativas, realizando o Connecticut Chemosensory Clinical Research Center Olfactory test. Resultados: Foram incluídos um total de 33 (55%) homens e 27 (45%) mulheres. A idade média foi 48,18 ± 13,88 anos (variação: 19-70 anos). As funções olfativas pré e pós-operatórias não apresentaram diferença estatisticamente significante dentro dos grupos no pós-operatório (p > 0,05). A memória olfativa pré e pós-operatória não mostrou diminuição estatisticamente significante quando avaliada três horas após a cirurgia (p< 0,05). Conclusões: Memória e funções olfativas não foram alteradas pelo desflurano no pós-operatório imediato. Embora o sevoflurano não tenha alterado as funções olfativas, causou efeito temporário negativo na memória olfativa no pós-operatório imediato.

Chronic treatment with carvacrol improves passive avoidance memory in a rat model of Parkinson's disease / O tratamento com carvacrol melhora a memória de esquiva passiva em um modelo da doença de Parkinson em ratos

ABSTRACT The present study investigated the effects of carvacrol on motor and memory deficits as well as hyperalgesia in the 6-OHDA-lesioned rat model of Parkinson's disease. The animals were subjected to unilateral microinjection of 6-OHDA into the medial forebrain bundle and treated with carvacrol (25, 50 and 100 mg/kg, ip) for six weeks after surgery. The 6-OHDA-lesioned rats showed contralateral rotations towards the lesion side, which was accompanied by learning and memory deficits in a passive avoidance test and a decrease in tail withdrawal latency in a tail flick test at the end of week 6. The results also showed that treatment with carvacrol at a dose of 25 mg/kg ameliorated memory deficits, with no effect on rotations and hyperalgesia in lesioned rats. In conclusion, carvacrol improves memory impairments in rats with Parkinson's disease; therefore, it may serve as an adjunct therapy for the alleviation of memory deficits in Parkinson's disease patients.

RESUMO O presente estudo investigou os efeitos do carvacrol nos déficits motores e de memória, bem como na hiperalgesia, em um modelo da doença de Parkinson (DP) em ratos com lesões 6-OHDA. Os animais foram submetidos a microinjeção unilateral de 6-OHDA no feixe mediano do prosencéfalo e tratados com carvacrol (25, 50 e 100 mg / kg, ip) durante 6 semanas após a cirurgia. Os ratos com lesões 6-OHDA mostraram rotações contralaterais para o lado da lesão, que foram acompanhadas de déficits de aprendizagem e de memória em um teste de evitação passiva, e de uma diminuição da latência de retirada da cauda em um teste de cauda no final da semana 6. Os resultados também mostraram que o tratamento crônico com carvacrol a uma dose de 25 mg / kg aliviou os déficits de memória, sem efeito sobre rotações e hiperalgesia em ratos lesados. Em conclusão, o carvacrol melhora a deficiência de memória em ratos com DP e, portanto, pode servir como uma terapia complementar para aliviar os déficits de memória em pacientes com DP.

Crack-cocaine dependence and aging: effects on working memory

Objective: To compare the working memory (WM) performance of young adult crack-cocaine dependent users, healthy older adults, and a control group of healthy young adults. Methods: A total of 77 female participants took part in this study: 26 young adult crack-cocaine dependent users (CRK), 19 healthy older adults (HO), and 32 healthy younger adults (HC). All participants completed the N-back verbal task. Results: A multivariate analysis of covariance was performed. The model included education, income, and medication use as covariates. A group effect (F6,140 = 7.192, p < 0.001) was found. Post-hoc analyses showed that the performance of the CRK and HO groups was reduced compared to the HC group in two N-back conditions. No differences between the HO and CRK groups on WM performance were found. Conclusions: CRK participants perform similar to HO participants on a WM task, despite the well-known effects of age on WM and the young age of CRK. These data point to a possible parallel between cognitive declines associated with crack use and developmental aging.

Working memory in Parkinson's disease patients: clinical features and response to levodopa / Memória de trabalho em pacientes com doença de Parkinson: características clínicas e resposta a levodopa

OBJECTIVE: To evaluate the clinical features of the working memory (WM) in Parkinson's disease (PD) patients and to test the effect of levodopa on WM. METHOD: The paradigm was based on the 'n-back' tasks, which enables to study the level of executive demand (three levels of difficulty) and the domain of the information being processed (spatial items, faces and letters). The effect of levodopa was studied by testing PD patients in "on" and "off" states. RESULTS: PD patients performed less well in WM tasks than controls. There was no interaction between groups and complexity. Levodopa therapy had a positive effect only on spatial WM tasks but no effect on complexity. CONCLUSION: Our results suggest that impairment observed may result from a maintenance deficit within WM regardless the level of processing and levodopa therapy presents a positive effect on spatial WM.

OBJETIVO: Avaliar as características clínicas da memória de trabalho (MT) em pacientes com doença de Parkinson (DP) e testar o efeito da levodopa na MT. MÉTODO: O paradigma baseou-se nas tarefas 'n-back', que permitem avaliar o nível de demanda executiva (três níveis de dificuldade) e o domínio da informação sendo processado (posições espaciais, faces e letras). O efeito da levodopa foi estudado pela testagem dos pacientes no estado "on" e "off". RESULTADOS: Pacientes com DP apresentam desempenho inferior ao dos controles em tarefas de MT. Não foi observada interação entre grupos e complexidade. A terapia com levodopa mostrou efeito positivo sobre a modalidade espacial, e nenhum efeito sobre a complexidade. CONCLUSÃO: Nossos resultados sugerem que o comprometimento observado pode resultar de défict de manutenção da MT, independente do nível de processamento. A terapia com levodopa apresenta efeito positivo sobre a MT espacial.

Choline supplementation facilitates short-term memory consolidation into intermediate long-term memory of young Sprague-Dawley rats / La suplementación con colina facilita la consolidación de la memoria a corto plazo y su transformación en memoria intermedia a largo plazo, en las Ratas Sprague-Dawley jóvenes

Choline is important for the synthesis of acetylcholine, an integral neurotransmitter involved in memory formation. In order to investigate the effect of choline supplementation on memory consolidation, the study utilized a T-maze to facilitate passive avoidance learning and memory in young female Sprague-Dawley rats. Rats were placed in two groups; choline-supplemented that received choline chloride daily for two weeks, and control that received vehicle daily for two weeks. Rats were evaluated to determine their ability to avoid an aversive electric foot-shock (0.1 mA at 60V) when they characteristically entered the preferred dark area (DA) of the T-maze. Both groups of rats showed preference, without significant difference, for entry into DA of the T-maze. However, fifteen minutes after passive avoidance both choline supplemented and control rats avoided entry into DA. This display of DA avoidance 15 minutes after training, suggests that both groups of rats had acquired short-term memory of the aversive stimulus. However, when the test was repeated 24 hours after training, the control group did not avoid entry into DA, whereas the choline-supplemented group either avoided entry or entered after a significantly longer latency period (p < 0.01). These results suggest that supplementation with choline facilitated the consolidation of short-term memory of the avoidance learning into intermediate long-term memory in young rats.

La colina es importante para la síntesis de la acetilcolina – un neurotransmisor integral que participa en la formación de la memoria. Para investigar el efecto de la suplementación con colina en la consolidación de la memoria, el estudio utilizó un laberinto T para facilitar la memoria y el aprendizaje de evitación pasiva en ratas hembras jóvenes Sprague-Dawley. Las ratas fueron colocadas en dos grupos: uno que recibió cloruro de colina diariamente por espacio de dos semanas, y uno de control que recibió vehículo diariamente por dos semanas. Las ratas fueron evaluadas a fin de determinar su habilidad para evitar un choque eléctrico aversivo (0.1mA a 60V) cuando entraban característicamente a la preferida área oscura (AO) del laberinto en T. Ambos grupos de ratas mostraron preferencia – sin diferencia significativa – por entrar en el área oscura del laberinto en T. Sin embargo, quince minutos después de la evitación pasiva, tanto las ratas que recibieron la suplementación con colina como las ratas de control, evitaban entrar al área oscura. El hecho de que se observe la evitación del área oscura15 minutos después del entrenamiento, sugiere que ambos grupos de ratas habían adquirido una memoria a corto plazo del estímulo aversivo. Sin embargo, cuando la prueba se repitió 24 horas después del entrenamiento, el grupo de control no evitó el entrar al AO, mientras que el grupo que recibió el complemento de colina, o evitó entrar o entró luego de un período de latencia significativamente más largo (P < 0.01). Por lo tanto, estos resultados sugieren por consiguiente que la suplementación con colina facilitó la consolidación de la memoria a corto plazo del aprendizaje de la evitación, y su transformación en memoria a largo plazo en las ratas jóvenes.

Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC) affects differently working and long-term memory on two foraging tasks

Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC) was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable.

Differential role of entorhinal and hippocampal nerve growth factor in short- and long-term memory modulation

We studied the effects of infusion of nerve growth factor (NGF) into the hippocampus and entorhinal cortex of male Wistar rats (250-300 g, N = 11-13 per group) on inhibitory avoidance retention. In order to evaluate the modulation of entorhinal and hippocampal NGF in short- and long-term memory, animals were implanted with cannulae in the CA1 area of the dorsal hippocampus or entorhinal cortex and trained in one-trial step-down inhibitory avoidance (foot shock, 0.4 mA). Retention tests were carried out 1.5 h or 24 h after training to measure short- and long-term memory, respectively. Immediately after training, rats received 5 æl NGF (0.05, 0.5 or 5.0 ng) or saline per side into the CA1 area and entorhinal cortex. The correct position of the cannulae was confirmed by histological analysis. The highest dose of NGF (5.0 ng) into the hippocampus blocked short-term memory (P < 0.05), whereas the doses of 0.5 (P < 0.05) and 5.0 ng (P < 0.01) NGF enhanced long-term memory. NGF administration into the entorhinal cortex improved long-term memory at the dose of 5.0 ng (P < 0.05) and did not alter short-term memory. Taken as a whole, our results suggest a differential modulation by entorhinal and hippocampal NGF of short- and long-term memory.

Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades

Since William James (1890) first distinguished primary from secondary memory, equivalent to short- and long-term memory, respectively, it has been assumed that short-term memory processes are in charge of cognition while long-term memory is being consolidated. From those days a major question has been whether short-term memory is merely a initial phase of long-term memory, or a separate phenomena. Recent experiments have shown that many treatments with specific molecular actions given into the hippocampus and related brain areas after one-trial avoidance learning can effectively cancel short-term memory without affecting long-term memory formation. This shows that short-term memory and long-term memory involve separate mechanisms and are independently processed. Other treatments, however, influence both memory types similarly, suggesting links between both at the receptor and at the post-receptor level, which should not be surprising as they both deal with nearly the same sensorimotor representations. This review examines recent advances in short- and long-term memory mechanisms based on the effect of intra-hippocampal infusion of drugs acting upon neurotransmitter and signal transduction systems on both memory types.

Contaminación de interiores: memoria y tabaquismo / Indoor pollution: Memory and tobacco habit

El tabaquismo es un problema de salud que ha despertado gran interés, debido a la importancia de las enfermedades que se relacionan con el hábito tabáquico. La mayoría de las investigaciones que al respecto se han realizado están enfocadas desde un punto de vista somático y son menos numerosas las que abordan el aspecto psicológico. La presente investigación tuvo como objetivo medir la memoria a corto plazo en un grupo de estudiantes del nivel medio de educación, empleando la prueba de David Wechsler modificada. La población estuvo integrada por 119 no fumadores y 89 fumadores. La prueba estadística chi cuadrada no mostró diferencias significativas en la memoria a corto plazo entre los grupos de fumadores y no fumadores

(+/-)Baclofen sensitive scopolamine-induced short-term memory deficits in mice.

Possible involvement of GABA receptor systems in scopolamine-induced short-term memory deficits was investigated using latency of mice to reach shock-free zone (SFZ) and number of mistakes (descents) the animal made in 15 min as parameters for acquisition and retention of memory in passive avoidance paradigm. Atropine (1-5 mg/kg), scopolamine (0.1-0.5 mg/kg) but not pirenzepine (5-20 mg/kg) caused disruption of memory. GABA (50, 75 and 100 mg/kg) showed retention enhancing effects in scopolamine-treated and untreated animals but GABA agonist progabide (5-20 mg/kg) did not affect any of the parameter significantly. GABAA agonist, muscimol (0.05 and 0.1 mg/kg) and GABAB agonist, (+/-)baclofen (0.25, 0.5 and 1 mg/kg) and (-)baclofen (0.25 and 0.5 mg/kg) also displayed memory enhancing action. Whereas, GABAA antagonist, bicuculline produced hind limb rigidity, GABAB antagonist, CGP 35348 did not show any effect per se, but reversed the (+/-)baclofen-induced delay in latency, without affecting retention enhancing action of (+/-)baclofen. Combined administration of subeffective dose of GABA (50 mg/kg) and (+/-)baclofen (0.25 mg/kg), showed a significant improvement in acquisition and retention. However, the effect of GABA (100 mg/kg) on acquisition was reversed by bicuculline (2 mg/kg) and by CGP 35348 (100 mg/kg) while improving retention. The present study extends support to the cholinergic concept in cognitive performance and provide an evidence for the influence of GABAergic (particularly GABAB) modulation in scopolamine-induced learning and memory deficits in mice.

Behavioural change in rats due to chronic oral and systemic formaldehyde.

Impact of chronic formaldehyde exposure in respect of route on behaviour was studied. Preconditioned (environmental) male albino rats (340-400 g) in 3 groups (n = 5) under 60 days oral and systemic exposure to 10 mg/kg/day HCHO were examined for their behavioural performance (i.e. short term memory) in Cook's apparatus. Twenty percent rats settled in grade III (unconditioned avoidance response) in the i.p. (i.e. systemic group) whereas in oral fed (HCHO route in drinking water) rats, 60% settled in grade II (conditioned avoidance response) at the end of sixty days.

Effect of physostigmine and atropine on the single-trial passive avoidance response in rats.

Rats received a single training trial on an inhibitory avoidance (passive avoidance) task and retention trials 24 hr (R-I) and 48 hr (R-II) later, in a special two-chambered apparatus, and the mean step-through latency was determined. The animals were given the drug, either pre-trial, pre-trial plus pre-retention, pre-retention or post-trial. Physostigmine (0.1 mg/kg, ip) and atropine (6.0 mg/kg, ip) had no effect on learning, but they adversely affected retention, particularly at 24 hr. The effect seems to involve central cholinergic mechanisms of retention.