All living organisms exhibit circadian rhythms. Humans show circadian rhythm of the different physiological functions such as sleep-wake cycle, core body temperature, feeding behavior, metabolic activity, heart rate variability, hormone secretion, and others. The hypothalamic suprachiasmatic nucleus (SCN) acts as a primary circadian pacemaker. Peripheral tissues have an endogenous circadian clock; however, SCN synchronizes the circadian activity of the peripheral clocks. The retinohypothalamic tract (RHT) from retinal ganglionic cells carries the photic signal into the SCN that regulates the rhythmic expression of the core clock genes through the feedback loop. At the output level, the SCN connects with the pineal gland and the peripheral tissues with the help of neuroendocrine mediators. Disruption of circadian clock functions is detrimental to health. Shift work, night work, chronic or acute jet lag, and light-at-night have adverse effects on circadian functions. Misalignment of circadian rhythm alters the expression of core clock genes, leading to deregulation of cellular activity and metabolic functions. Circadian rhythm dysfunction causes many pathologic conditions, including sleep disorders, cardiovascular problems, metabolic dysfunction, infertility, poor physical performance, as well as cancer. The present work has reviewed the relationship between circadian clock dysfunction and impaired physiological activities.

Neuregulins (NRGs) and their cognate ErbB receptors (ErbB2–ErbB4) constitute a vast group of proteins encoded by six different genes (NRG1–6) and many isoforms with critical roles in the development and functioning of the nervous system. NRGs are known to regulate important processes in the nervous system like neural development, neuronal differentiation, neurite outgrowth, and specification. These factors are involved in the regulation of neurotransmission pathways and the modulation of several forms of synaptic plasticity. Due to NRGs’ role in synaptic plasticity, defects in their normal functioning are translated into altered signaling networks, which have been linked to susceptibility to developing psychiatric disorders like schizophrenia (SZ), autism, depression, and bipolar disorders. Additionally, deviation of the NRG normal functioning is involved in neurological diseases like Alzheimer’s and Parkinson’s disease. Contrastingly, NRG/ErbB signaling is also involved in the recovery after traumatic brain injuries (e.g., ischemic stroke). The NRG/ErbB signaling complex is highly unusual because the ligands (mainly NRG1–NRG3, with their multiple isoforms) and receptors (ErbB2–ErbB4) can orchestrate vast signaling complexes, with a wide reach within the processes that govern the development and appropriate function of the nervous system. This may explain why NRGs and ErbB receptor genes have been linked to complex brain disorders, like SZ. This review, are discussed important aspects of NRG and their relevance for nervous system functioning, including 1) subcellular localization, 2) signaling pathways involved in neuronal functions, 3) effect on neurite development and synapse formation, 4) modulation of some mechanisms of synaptic plasticity [long-term potentiation (LTP), depotentiation, long-term depression (LTD)] and 5) roles of NRGs in some neurological diseases. This review intends to present a summary of the main findings about this family of proteins, which might position them as one of the master regulators of brain functioning.

This brief statement describes some recent achievements of neuropathological research, with the focus on Alzheimer’s and other age-related diseases, neurodegenerative disorders (tauopathies, synucleinopathies), multimorbidity of the aged brain, multiple sclerosis (MS), and other neuroinflammatory disorders, including central nervous system involvement by coronavirus disease 2019 (COVID-19), as well as new developments in neurovascular diseases, neurooncology, and myopathies. Although neuropathology, using modern technologies, such as cryo-electron microscopy, proteomic and experimental methods, has helped to increase diagnostic accuracy and provided insight into the pathogenesis of many neurological disorders, future studies in co-operation with clinical and other neurosciences should overcome the challenges of disease-influencing therapeutic approaches.

Ischemic stroke is a highly prevalent condition that frequently results in life-long disability and death. Considerable efforts have been made to establish treatments that prevent secondary ischemic damage and promote stroke recovery. Until now, the recanalization of occluded blood vessels via thrombolysis and thrombectomy, although highly potent, remains the only treatment in humans that enhances stroke outcome. Small extracellular vesicles are non-replicating, nano-sized (70–150 nm) lipid bilayer-enclosed vesicles, which have shown remarkable biological activities in various physiological and pathophysiological contexts. When administered post-stroke, mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) induce neuroprotection, promote brain remodeling and plasticity, and enhance neurological recovery in rodents and non-human primates via mechanisms that involve immunomodulation and anti-inflammation. In this review, experimental studies on the therapeutic actions of MSC-EVs in animal stroke models are summarized and perspectives for clinical translation are outlined.

Brain development, a complex process, consisting of several phases, starting as early as two weeks after conception, and continuing through childhood till early adolescence, is crucial for the development of properly functioning body systems, behavioral traits, and neurocognitive abilities. Infancy and childhood are recognized as important periods for initial brain formation, however in later stages of life, such as childhood and adulthood, experiences, together with environmental exposures, can still influence brain physiology. The developing brain is particularly susceptible to epigenetic changes with many factors being proposed as modifiers by directly impacting DNA methylation as well as histone and chromatin modifications within genes implicated in development. These factors include: maternal stress and diet, exposure to pollutants, sleep quality, as well as dietary habits. Evidence indicates exposures to environmental threats can lead to inappropriate neurological, metabolic, and endocrine functioning often mediated by epigenetic mechanisms with symptoms manifesting themselves as early as childhood or in later stages of life. Therefore, the main aim of this review is to evaluate the current studies focused on negative environmental exposures and their consequences on the developing brain directed by epigenetic mechanisms.

Life is the highest form of adaptation to the environment which is based on energy metabolism. To maintain life, the neuromuscular system must constantly interact with the environment. The striatal muscles are the main energy consumer and their access to energy fuel is mainly limited by the brain’s needs. In the state of wakefulness, the brain must continuously process streams of sensory signals and respond to them with motor actions. At the same time, the brain to be efficient must memorize the sensory-movement relationships. Brain memory networking requires additional energy allocation, and due to limited systemic energy resources, the processes of memorization are completed during the sleep phase when the inactive muscular system allows allocating the energy fuel to the brain functions such as memory trace formation and the removal of the activity-dependent waste products. Both physiological processes can be completed during sleep only, and consequently, chronic sleep disorder leads to pathological changes in brain functioning and escalation of neurodegenerative processes. Consequently, sleep disorders become the main cause of dementia which is the prodrome of Alzheimer’s disease.

As the average lifespan has increased, memory disorders have become a more pressing public health concern. However, dementia in the elderly population is often neglected in light of other health priorities. Therefore, expanding the knowledge surrounding the pathology of dementia will allow more informed decision-making regarding treatment within elderly and older adult populations. An important emerging avenue in dementia research is understanding the vascular contributors to dementia. This review summarizes potential causes of vascular cognitive impairment like stroke, microinfarction, hypertension, atherosclerosis, blood-brain barrier dysfunction, and cerebral amyloid angiopathy. Also, this review address treatments that target these vascular impairments that also show promising results in reducing patient’s risk for and experience of dementia.

The two mainstays of therapy for refractory epilepsy are medication and surgery. Child behavioral and cognitive aspects of epilepsy can be improved by using a specialized dietary regimen such as the ketogenic diet (KD). The purpose of this review is to expand our understanding of KD as a nutritional therapy for children with refractory epilepsy and to provide insight into the physiological aspects of its efficacy as an alternative to anti-seizure medication. Either directly or indirectly, ketones, glucose restriction, and polyunsaturated fatty acids regulate epileptic seizures. For KD to be effective, all three of these components must be present, even though the exact mechanism is unknown. Increasing gamma-aminobutyric acid, mitochondrial biogenesis, and oxidative phosphorylation levels can also serve as a means of promoting stable synaptic function while also decreasing neural activity and excitability. Most side effects of KD are caused by mild metabolic abnormalities such as acidosis, hyperuricemia, hypercholesterolemia, hypocalcemia, and hypomagnesemia. Since medium-chain triglycerides (MCTs) produce more ketones per calorie than long-chain triglycerides, individuals who consume MCTs can consume more carbohydrates and protein. This review demonstrated that KD therapy led to positive outcomes for patients with refractory epilepsy. Further study is needed to evaluate whether less restrictive and easier-to-follow diets, such as the modified Atkins diet and MCT diets, have a similar effect on seizure treatment as the standard KD.

Epilepsy, a prevalent neurological disorder, is characterized by chronic seizures resulting from abnormal electrical activity in the brain. Adequate medical treatment allows roughly 70% of patients to enjoy a seizure-free life. However, throughout history, epilepsy has acquired diverse interpretations due to the experienced seizures, transforming the condition from a clinical issue into a social stigma. Therefore, the aim of this review study is to review stigma and psychosocial problems in patients with epilepsy (PwE). For this reason, this study utilises sources from the last ten years and reports current data. As a result of the review, it was found that societal discrimination in PwE arises primarily from inadequate knowledge, misconceptions, and negative attitudes toward the condition. Other contributing factors were include patients’ lower levels of education and income, frequent seizures due to inadequate treatment, age at onset, duration of the disease, depressive symptoms, and lack of social support. Also, it was found that the stigma individuals with epilepsy face plays a pivotal role in exacerbating their psychosocial problems. Unfortunately, stigma and psychosocial challenges appear to be in a vicious circle, with an increase in one increasing the other. Stigmatized patients tended to isolate themselves from society, further increasing their likelihood of experiencing a depressive mood or psychiatric comorbidity. Consequently, individuals with epilepsy encounter difficulties in various domains such as marriage, work, education, and personal life. Considering these significant psychosocial burdens, it is essential to recognize that epilepsy surpasses its medical implications. Unfortunately, current efforts to reduce stigma remain insufficient, necessitating urgent and comprehensive measures to address this issue.

Neuropathic pain is an increasingly common disease affecting millions of individuals worldwide. Refractory pain poses a significant impact on patients’ quality of life, financial and economic stability, and social interaction. Numerous effective modalities for treatment of refractory neuropathic pain are presently available. Currently, many options provide symptomatic treatment but are associated with an unfavorable side effect profile and increased risk of addiction. The present investigation reviews current medical management for refractory neuropathic pain including the use of antidepressants, anticonvulsants, gabapentinoids and opioid therapy, as well as interventional pain procedures such as spinal cord stimulation (SCS) and intrathecal targeted drug delivery. While multidisciplinary management with lifestyle modification and pharmacologic regimens remains at the forefront of treating many of these patients, interventional modalities are growing in popularity and have been demonstrated to be highly efficacious. In this regard, continued understanding of the pathophysiology surrounding refractory neuropathic pain has led to the development of interventional procedures and better outcomes for patients suffering from refractory neuropathic pain. When and if patients fail conservative therapy, interventional techniques are desirable alternatives for pain management. SCS and intrathecal targeted drug delivery are important tools for the treatment of refractory neuropathic pain. In summary, treatment modalities for refractory neuropathic pain are evolving with demonstrated efficacy. This review aims to outline the efficacy of various interventional procedures for refractory neuropathic pain in comparison to traditional drug therapies.

The circadian rhythm is a critical system that governs an organism’s functions in alignment with the light-dark cycle. Melatonin release from the pineal gland plays a crucial role in regulating the internal clock of the body. Multiple neurotransmitter systems in the central nervous system are linked to the release of melatonin. In this review, the relationship between circadian rhythm, melatonin secretion and various neurotransmitter systems are mainly discussed. Serotonin regulates the circadian rhythm through projections from raphe nuclei. Agomelatine is an example of the synergistic interaction between melatonin and serotonin. Melatonergic agents and selective serotonin reuptake inhibitors also exert notable impacts on depression in concomitant use. Dopamine has an inhibitory effect on melatonin release, while melatonin also inhibits dopamine release. This should be taken into account when considering the use of melatonin in Parkinson’s disease. On the contrary, use of melatonin may offer therapeutic advantages for schizophrenia and tardive dyskinesia. The interaction between norepinephrine and melatonin exhibits diurnal variability, with norepinephrine promoting arousal and inhibiting daytime melatonin secretion. Melatonergic neurons also exert a specific protective influence on cholinergic neurons. Interaction between the histaminergic and melatonergic systems is significant, particularly in association with immunity, sleep, and circadian rhythm. Novel ligands with dual-acting properties, interacting with both the histaminergic and melatonergic systems are investigated. Currently, there is a limited number of approved melatonergic agents that primarily demonstrate positive effects in addressing insomnia and depression. However, there is considerable potential in studying new agents that target both the melatonergic and other neurotransmitter systems, which alleviate various conditions, including neurodegenerative diseases, dementia, autoimmune diseases, allergic diseases, epilepsy, and other neuropsychiatric disorders. The ongoing process of developing and evaluating new ligands selectively targeting the melatonergic system remains crucial in understanding the complex relationship between these systems.

Neural disorders refer to conditions of the nervous system due to infection or degeneration of the neurons leading to either neurodegenerative disorder or neuropsychiatric disorder. Some such disorders of the nervous system include Parkinsons’s disease, depression, amnesia, dementia, Alzheimer’s disease, schizophrenia, cerebrovascular impairment, epilepsy, seizure disorders, etc. In conventional medical system, some medicines belonging to the class of psychodelic drugs, sedatives, neurotransmitters, neuro-stimulants, etc. are in extensive use. Unfortunately, most of these drugs either delay the progression of the neural disorder or leave the patient with prominent adverse side effects. Several potent bioactive compounds with neuroprotective potential have been reported from medicinal plants and some of them have been found to be highly effective. Belonging from natural sources, mostly, the plant derived compounds exhibit minimum or no cytotoxicity at a prescribed standardised dose against a particular health ailment. Many such phytocompounds from plant sources with potent neuroprotective activities have been in use in Ayurvedacharya, Unani, and Chinese medicine for ages. The compounds if isolated chemically, modified to make more potent neuroprotective derivatives and utilised to make highly effective neuroprotective pharmaceutical formulations with minimum side effects, may open new revolutionary doorways in neuropharmacology. In this review, it has been briefly discussed about the neuroprotective compounds isolated from certain indigenous plants of West Bengal, India, and their mechanism of action.

Hemangioblastoma are benign, vascularized cranial tumors caused by autosomal dominant inherited von Hippel-Lindau disease or can appear sporadically. This review will investigate current and emerging treatments for cerebral tumors. It will focus on the current and, more importantly, developing hemangioblastoma treatments. Surgical resectioning and radiotherapy are effective treatment options for cerebral tumors, whereas chemotherapies are not commonly used due to their limited ability to penetrate the blood-brain barrier. Recent chemotherapies have shown promise, but further research is needed to determine the efficacy as a treatment for hemangioblastomas. New advances in brachytherapy and immunotherapy are considered promising treatment options for hemangioblastoma. This review aims to offer valuable insights into the latest developments in hemangioblastoma treatments.

Bipolar disorder (BD) is a debilitating psychiatric disorder characterized by recurrent depression, mania, and hypomania episodes. The interaction of psychological, neuropsychological, and neurobiological factors (cognitive, behavioral, and emotional) is implicated in the development and persistence of BD. Accordingly, almost all investigators confirm that BD is the outcome of psychological and genetic interactions. Therefore, researchers should consider various factors in the psychopathology and psychotherapy of BD. This selective review first reviews research on these factors, then points to a variety of therapeutic methods for BD [interpersonal and social rhythm therapy (IPSRT), cognitive behavioral therapy (CBT), dialectical behavior therapy (DBT), mindfulness-based cognitive therapy (MBCT), and family-focused therapy (FFT)], and finally suggested a new comprehensive integrated model for the assessment and therapy of BD.

Receptor tyrosine kinases (RTKs) are known to perform versatile roles in disease landscapes, which determine the fate of the cell. Although much has been discussed from the perspective of proliferation, this review focuses on the impact of RTK-mediated signaling and its role in cytoskeletal degradation, the penultimate stage of cellular degeneration. In the case of degenerative diseases such as Alzheimer’s disease (AD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD), age-related macular degeneration (AMD), and type 2 diabetes mellitus (T2DM), RTK signaling has been reported to be perturbed in several studies. The implications of downstream signaling via these receptors through canonical and noncanonical pathways alter the status of actin filaments that provide structural integrity to cells. Degenerative signaling leads to the altered status of rat sarcoma (Ras), Ras homologous (Rho), Ras-related C3 botulinum toxin substrate (Rac), and cell division control protein 42 (Cdc42), the best-characterized components of the cytoskeleton remodeling machinery. RTKs, along with their diverse adaptor partners and other membrane receptors, affect the functionality of Rho family guanosine triphosphate hydrolases (GTPases), which are discussed in this review. To conclude, this review focuses on therapeutic strategies targeting RTKs and Rho GTPase-mediated pathways that can be more effective due to their combined multifactorial impact on neurodegenerative cascades.

Proprioception provides important sensory feedback regarding the position of an animal’s body and limbs in space. This interacts with a central pattern generator responsible for rhythmic movement, to adapt locomotion to the demands that an animal’s environment places on it. The mechanisms by which this feedback is enabled are poorly understood, which belies its importance: dysfunctional proprioception is associated with movement disorder and improving it can help reduce the severity of symptoms. Similarly, proprioception is important for guiding accurate robotic movement and for understanding how sensory systems capture and process information to guide action selection. It is therefore important to interpret research that investigates mechanisms of proprioception, to ask: what type of information do proprioceptive sensors capture, and how do they capture it? Work in mammalian models has made important progress towards answering this question. So too, has research conducted Drosophila. Fruit fly proprioceptors are more accessible than mammalian equivalents and can be manipulated using a unique genetic toolkit, so experiments conducted in the invertebrate can make a significant contribution to overall understanding. It can be difficult, however, to relate work conducted in different models, to draw general conclusions about proprioception. This review, therefore, explores what research in the fruit fly has revealed about proprioceptor function, to highlight its potential translation to mammals. Specifically, the present text presents evidence that differential expression of mechanoelectrical transducers contributes to tuning of fly proprioceptors and suggests that the same mechanism may play a role in tuning mammalian proprioceptors.