The gamma-aminobutyric acid type A receptors (GABAA Rs), belonging to the superfamily of Cys-loop receptors, responsible for the inhibitory transmission in the vertebrate central nervous system. Assembled from a pool of 19 subunits, the subunit composition of heteropentameric GABA-A Rs impacts on receptor’s function, physiology, cellular and subcellular localization in the cell membrane, i.e., synaptic or extrasynaptic. γ2 containing GABA-A Rs (γ2-GABA-A Rs) are clustered in the synapses and mediate classical fast synaptic inhibition called phasic inhibition. δ subunit containing GABA-A Rs (δ-GABA-A Rs) are located extrasynaptically and mediate a different form of inhibition called tonic inhibition critical for the threshold of action potential generation and neuronal excitability. Thus, distinct physiological roles of synaptic and extrasynaptic GABA-A R subtypes lead to the question to ask about the possibility of subtype selective drugs. In the light of accumulating data from X-ray crystal structures of vertabrate, invertabrate and prokaryotic Cys-loop receptor family members, new opportunities arise for the development of novel drugs targeting specificaly these subtypes of GABA-A Rs for the treatment of various neuropathological conditions.

Olfactory function comes into prominence in the neuroscience study area after revealing that olfactory dysfunction is considered as an early diagnostic pre-motor biomarker of Parkinson’s disease. Researchers have also examined the sense of smell in detail in patients with other neuropsychiatric disorders. Here, we present data from a systematic literature review in olfactory function in child and adult neuropsychiatric disorders. We have researched autism spectrum disorders (ASD), epilepsy, attention-deficit/hyperactivity disorder (ADHD), schizophrenia, bipolar disorder, eating disorders, and obsessive-compulsive disorder (OCD). Due to smell test techniques and heterogeneity of studies, the total number of studies was limited. The disorders were grouped according to smell test techniques. The most commonly-used tests were Sniffin Sticks Test (SST) and the University of Pennsylvania Smell Identification Test (UPSIT). Although some researcher did not find any significant impairment in olfaction, most studies indicated that olfactory dysfunction was very striking, especially in disorders involving in the dopaminergic pathway (e.g., ADHD, autism, and schizophrenia). In this review, possible future diagnostic or prognostic markers of olfactory dysfunction in neuropsychiatric disorders have been discussed. More studies that combine imaging methods, the electrophysiologic system, and genetic research are needed to clarify the relationship between olfaction and neuropsychiatric disorders.

The Biased Competition Model suggests that stimuli matching the contents of working memory increase the likelihood that memorymatching items will be attended. According to this account, the representations in working memory create an involuntary capture of attention toward memory-matching items in the visual field. This influential assumption proposed by the biased competition model has been explored in a number of studies, showing that the contents of working memory exert an automatic bias in favor of memory matching items. These studies showed that active maintenance of objects in working memory automatically shift attention toward the memory matching-object and produce a negative early lateralized event related potential (ERP), the N2pc, toward the side of visual field where the memorized item appeared. This component, the N2pc is an important tool to investigate the allocation of attention by working memory representations, especially for the activity the activity that is specific to the hemisphere which is contralateral with respect to the hemifield containing e.g. the to-be-remembered items could be measured. This characteristic of the N2pc facilitates measuring the general direction of attention with fine-grained temporal resolution. Therefore, the N2pc could be used as an index to describe the lateralization effect of memorized items on attention related studies.

Most of the patients with temporal lobe epilepsy suffer from memory decline following anterior temporal lobectomy (ATL). Studies examining memory decline following ATL show that post operative memory decline can be predicted in advance through the pre operative determination of memory lateralisation. Therefore, preoperative memory lateralisation plays a crucial role for epileptic surgery. Recent research suggests that instead of WADA test which is known as an invasive and high-risk operation, functional MRI can be used as a non-invasive and repeatable method to lateralize memory in the brain and to predict post operative memory decline. The aim of this article is to review the utility of fmri in prediction of post operative memory decline and to summarize the results of recent memory lateralisation studies using fmri.

The glutamate hypothesis of schizophrenia based on the observations that administration of drugs that block N-methyl-D-aspartate (NMDA) glutamate receptors could induce schizophrenia-like symptoms. There are several evidences linking abnormal glutamatergic transmission to cognitive, negative, and positive symptoms of schizophrenia and the glutamatergic system is now a major focus for the development of new compounds in schizophrenia. The polyamines are omnipresent aliphatic molecules comprising putrescine, spermidine, spermine and agmatine. The polyamines and their biosynthetic enzymes are found throughout the body, including the central nervous system (CNS), where they display specific regional distributions in the CNS. The polyamines have an important role in the modulation of cell growth and on cell membrane functions. It was hypothesized that schizophrenia may be related to a general abnormality in neuronal membranes. Agmatine, a polyamine, selectively blocks the NMDA subclass of glutamate receptors in rat hippocampal neurons. There are also several evidences indicate that a relationship between polyamines and etiopathogenesis of schizophrenia. In this review, a new approach for understanding schizophrenia via NMDA receptors and their interaction with agmatine which is a biological active polyamine transmitter in brain is proposed.

Polyamines, including spermidine, spermine, and agmatine, serve several brain-specific functions. Polyamine transport mechanisms may account for the redistribution of these organic cations, which may also be synaptically released as neuromodulators or neurotransmitters, in the brain. Therefore, the localization of polyamine pathway enzymes, in addition to the localization and functional investigation of the polyamines itself, provides valuable insights regarding the identification of cell- and region-specific roles for polyamines, notably in the context of mental disorders and neurodegenerative diseases. Identified neuronal circuits are subject to physiological and pharmacological investigations. With this respect, we electrophysiologically studied the cerebellar cortex and the medial habenula, showing a prominent synaptic expression of spermidine synthase and agmatinase, respectively. In both areas, the relevant polyamines clearly influence the electrical activity. The medial habenula may be involved with the aetiology of major depressive disorder. In this context, the expression of agmatinase in other brain areas, e.g. the paraventricular thalamic nucleus, possibly also involved with depression, is discussed.

Blood injury injection phobia (BII) involves an intense fear of situations, in which an individual is directly or indirectly exposed to blood, injections or viewing injuries, along with a tendency to avoid these situations. BII phobia is highly prevalent in females as compared to males. It is virtually the only specific phobia and the only anxiety disorder, in which fainting occurs. Although fainting is much distressed to the BII phobic individuals, but it may have developed in the humans at the time when they needed it much as a survival mechanism. In this article we discuss how in the humans there may have developed the trait of BII phobia in the ancestors, including the variation in the symptoms among sexes. There are not studies which specifically examine the syncope related brain differences among genders. But there are other well defined studies which highlight marked differences among male and female brains. Considering this we also review some recent breakthrough discoveries showing differences in the brain of males and females at gene expression level which leads to the variation in brain and behaviour related problems among genders. There is an exigent need to understand the brain behavioral problems through multiple perspectives.

The olfactory system is vital mechanism for our survival to interact with the environment, influencing not only on odor detection but also on nutrition, social behavior and well-being. Current findings suggest that before the onset of any cognitive decline reflecting early sign of dementia, dysfunction in the areas processing olfactory information is present at the early stages of Alzheimer’s disease (AD). Behavioral test including thresholds, odor identification, recognition memory tasks are the most common types of odor measurement. However, recent neuroimaging techniques using measures of brain response, including Olfactory Event Related Potentials (OERPs) suggested the potential for detection of AD at the early preclinical stage. The importance of olfactory event related potentials and their relation with AD appear to be very promising.

Alcoholism is a disorder caused by an excessive and maladaptive pattern of alcohol consumption. A series of impairments can arise from such consumption, including psychiatric comorbidities. The objective of this study was to evaluate the rate of occurrence of anxiety and depression comorbidities in alcoholics and to investigate the associations of such comorbidities with the dose of ingested alcohol, period of alcohol use, personality traits and the presence of early emotional trauma. The sample consisted of 110 alcoholics, evaluated by the Structured Clinical Interview for DSM-IV (SCID-IV – clinical version) and recruited at the Hepatopathy Outpatient Service of a University Hospital. Data collection was individual and took place through the application of self-evaluation instruments. Statistical analysis was performed using parametric statistics with a significance level of p≤0.05. The main results showed that 46.3% of alcoholics had psychiatric comorbidities with mood disorders and/or anxiety. In addition, according to the logistic regression model, the increase in the doses of alcohol ingested and the presence of early emotional traumas were risk factors for the development of such comorbidities in alcoholics: (ODDS=1.18; p=0.005) and (ODDS=1.17; p=0.001), respectively. These data indicate the need for early intervention with regard to the primary care of both alcoholics who suffered early trauma and alcoholics who ingest large amounts of alcohol daily to decrease the risk of psychiatric comorbidities in this high-risk group.