Trichotillomania is a chronic mental disorder characterized by recurrent hair-pulling. Hoarding, excoriation and trichotillomania are classified as obsessive-compulsive related disorders in DSM-5, which share similar clinical presentations, characterized by inappropriate and excessive repetitive behaviors and dysregulation of inhibitory control processes. Research evidence suggests that abnormalities in the cortico-striato-thalamic-cortical circuits are one of the key factors underlying the pathophysiology of obsessivecompulsive related disorders, including trichotillomania. Glutamate is the primary neurotransmitter within the cortico-striato-thalamiccortical circuits. Therefore, the use of glutamate-modulating agents is subject to interest for obsessive-compulsive related disorders. N-acetylcysteine, a derivate of the amino acid L-cysteine, has been explored as potential therapy for obsessive-compulsive related disorders, including trichotillomania. Pharmacotherapies that target the prefrontal glutamatergic system, such as N-acetylcysteine, may correct the underlying pathophysiologic abnormalities and symptoms of trichotillomania. Even a limited number of studies are suggesting that N-acetylcysteine is a promising treatment option, these studies did not assess treatment effects exceeding 3-4 months treatment period. Longer term effects of N-acetylcysteine therapy in trichotillomania require further evaluation.

In this article, has been discussed the characteristics that make knowledge unforgettable. The attention has been attracted to the role of the involvement of multiple brain layers, locations and connections, in learning and performing process. It is sustained that “learning and performing are systemic issues” and proposed that “a successful learning and performance is directly proportional to the sum of created appropriate personal ties – created personal functional connectomes - in the entirety of the central nervous system” and the “strength or weakness of a learned material is directly proportional to the quantity, quality and intensity of the ties made within the entire Central Nervous System Network”. In other terms; the more brain parts are involved the better is learned and performed. And, it has been outlined that “the same fact is the explanation of why in different subjects, the memory storages are relatively in different localities, and in vague concentrations.”

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.