1,721,050 research outputs found
Serotonergic 5-HT7 receptors and cognition
No full textThe abundant distribution of serotonin (5-HT) in different areas of the central nervous system can explain the involvement of this neurotransmitter in the regulation of several functions, such as sleep, pain, feeding, and sexual and emotional behaviors. Moreover, the serotonergic system is also involved in other more complex roles, such as cognition, including learning and memory processes.
Recent studies led to the discovery of various types and subtypes of receptors differentially associated to cognitive mechanisms. 5-HT7 is the most recently discovered receptor for 5-HT; therefore, it is also one of the least well characterized. Studies exist hypothesizing the role of 5-HT7 on the modulation of learning and memory processes and other cognitive functions. Moreover, much attention has been devoted to the possible role of 5-HT7 receptors in psychiatric disorders. Therefore, the aim of this review is to clarify the behavioral role of the recently discovered 5-HT7 type receptor and highlight its involvement in the cognitive functions, with particular attention to the modulation
of learning and memory processes, thus providing a basis to obtain new therapeutic agents and strategies for the treatment of cognitive disorders
5-HT7 receptors in the modulation of cognitive processes
No full textThe abundance of serotonin (5-HT) in the central nervous system can explain its role in the regulation of various functions, such as sleep, feeding,sexuality, emotional status, and pain. In addition, 5-HT localized in “cognitive pathways” with hippocampus and frontal cortex as the main target
structures, is involved in learning and memory processes. Recent studies led to the discovery of various types and subtypes of receptors, differentially
associated to cognitive mechanisms. Abundant data available reveals that the administration of 5-HT2A/2C and 5-HT4 receptor agonists, or 5-HT1A,5-HT3 and 5-HT1B antagonists improves memory and has a facilitatory effect on learning in situations involving a high cognitive demand. On the contrary 5-HT2A/2C and 5-HT4 receptors antagonists, or 5-HT1A, 5-HT3 and 5-HT1B receptors agonists have opposite effects. Although these results
are contradictory, or even opposite, it is important to take into account the effect of global, and unspecific, stimulation of serotonergic receptors and the activation of other neurotransmission systems, together with the type of task used, the way it is administered and the ligand affinity.
The aim of this review is to clarify the behavioral role of the recently discovered 5-HT7-type receptor and highlight its involvement in the modulation of learning and memory processes, thus providing a basis to obtain new therapeutic agents and strategies for the treatment of learning and memory disorders
Neuropharmacological, Neurobiological and Behavioral Mechanisms of Learning and Memory
Full text linkThe relationship between Night Eating Syndrome, depression and chronotype in a non-clinical adolescent population
No full textPurpose. The aim of the current study was to assess the prevalence of Night Eating Syndrome (NES) in a population of non-clinical adolescents and to investigate the relationship between NES, depression and eveningness dimension. Methods. The data were collected from a sample of 301 subjects, 181 females and 120 males, aged between 15 and 19 (mean value 17.64, SD=1.3). All subjects were invited to answer demographic questions and to take a self-report battery composed by three questionnaires: the Night Eating Questionnaire (NEQ), the Morningness Eveningness Questionnaire (MEQ) and the Beck Depression Inventory (BDI). Results. The distribution of chronotypes in the sample was: morning type 9%, intermediate 68.4% and evening type 22.6%. 4% of the participants (12 subjects) reached the criteria for NES The data indicate that MEQ and NEQ scores are significantly inversely correlated (r=-0.157; p<0.01); 58.3% of the participants who reached the criteria for NES received low scores on the MEQ.The BDI scores resulted significantly associated with the NEQ variable (r=0.275; p=0.001). Conclusions. This is the first study, as far as we are aware, which has investigated the relationship between chronotype, depression and NES in an adolescent non-clinical population. The findings of our study highlight the high prevalence of NES in the adolescent population and indicate a significant association between eveningness dimension, Depression and NES
The role of endogenous fluctuations of estrogen on working and reference memory across the estrous cycle of female rat
No full textThe results of many studies conducted over the past two decades suggest a role for estrogen in
mammals'ability to learn and remember. In the present paper we analyzed the influence that the
endogenous fluctuation of estrogen, naturally present across the different phases of the estrous cycle
of female rats, can exert over the performance of tasks utilized to asses memory. In particular, we
analyzed the performances in an eight arm radial maze task, dependent upon working memory, and
in a water maze task, dependent upon spatial reference memory. The WM is aversively motivated by
the desire to escape onto a safe platform, whereas the RAM is motivated by food reward. The
difference in reinforcement may affect the speed of learning, the strategy adopted and the necessity
for accurate navigation. Therefore, coherent results obtained through the two different tasks can be
due to mnemonic factors.
The study was conducted during a long period of time, 14 months, utilizing gonadally intact females,
without pharmacological and surgical treatments. In order to evaluate the post-acquisition phase we
first trained the animals to reach the criterion in performing tasks, and then we submitted them to
experimental phase. Our results show that estrogen can have an effect on memory processes, and
that this effect may be different in relation to different kinds of memory. In fact, in our study, estrogen
selectively improved working memory, but not reference memory, during post-acquisition
performance of a radial maze task with four baited and four un-baited arms. Moreover, water maze
performances showed that estrogen has a negative effect on spatial reference memory
Physiological relevance of estrogen effects on memory across the menstrual cycle of young women
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Sex-related talkativeness and emotional memory
No full textEmotionally arousing events are more likely to be recalled compared to non-arousing events. Moreover, recent studies have begun to reveal seemingly large, but previously unsuspected, sex-related influences on this mechanism, and sex differences in cognition are consistently reported. Sex-related differences in language processing are well known from everyday life, as well as from the scientific literature. Our previous studies indicated that both sex and cerebral hemisphere constitute important interacting influences on neural correlates of emotion and emotional memory. Moreover, many data evidenced sex-related differences in language processing and conversational behaviour. Therefore, the aim of the present study was to evaluate possible talkativeness differences between the two sexes in the recollection of emotional stimuli, recording the number of words that men and women use when they are submitted to a declarative memory test, using two kinds of emotional stimuli: the International Affective Picture System (IAPS), a set of calibrated picture stimuli, and an Italian adaptation of two versions of a story, differing for their arousal characteristics (neutral and emotional), both widely used for investigating emotion and emotional memory. The evaluation of the number of words, utilized by men and women during the free recall of both kind of stimuli, showed that women used always an higher number of words compared to men. In conclusion, according to previous studies indicating that men and women process emotional stimuli differently, our findings suggest the existence of gender-related neural responses to emotional stimuli and could also contribute to the understanding of mechanisms underlying the gender disparity of neuropsychiatric diseases, such as mood disorders
Sex-related memory recall and talkativeness for emotional stimuli
No full textRecent studies have evidenced an increasing interest in sex-related brain mechanisms and cerebral lateralization subserving emotional memory, language processing, and conversational behavior. We used event-related-potentials (ERP) to examine the influence of sex and
hemisphere on brain responses to emotional stimuli. Given that the P300 component of ERP is considered a cognitive neuroelectric phenomenon, we compared left and right hemisphere P300 responses to emotional stimuli in men and women. As indexed by both amplitude and latency measures, emotional stimuli elicited more robust P300 effects in the left hemisphere in women than in men, while a stronger P300 component was elicited in the right hemisphere in men compared to women. Our findings show that the variables of sex and hemisphere interacted significantly to influence the strength of the P300 component to the emotional stimuli. Emotional stimuli were also best recalled when given a long-term, incidental memory test, a fact potentially related to the differential P300 waves at encoding. Moreover, taking into account the sex-related differences in language processing and conversational behavior, in the present study we evaluated possible talkativeness differences between the two genders in the recollection of emotional stimuli. Our data showed that women used a higher number of words, compared to men, to describe both arousal and neutral stories. Moreover, the present results support the view that sex differences in lateralization may not be a general feature of language processing but may be related to the specific condition, such as the emotional content of stimuli
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