Bilateral Synchronization of Hippocampal Early Sharp Waves in Neonatal Rats

In the neonatal rodent hippocampus, the first and predominant pattern of correlated neuronal network activity is early sharp waves (eSPWs). Whether and how eSPWs are organized bilaterally remains unknown. Here, using simultaneous silicone probe recordings from the left and right hippocampus in neonatal rats in vivo we found that eSPWs are highly synchronized bilaterally with nearly zero time lag between the two sides. The amplitudes of eSPWs in the left and right hippocampi were also highly correlated. eSPWs also supported bilateral synchronization of multiple unit activity (MUA). We suggest that bilateral correlated activity supported by synchronized eSPWs participates in the formation of bilateral connections in the hippocampal system

Emotional Dysregulation as a Factor of Psychosomatic Disturbances in Depression and Cardiovascular Pathology (Analytical Review of Foreign Literature)

The review presents data on cognitive processes of emotional regulation, which are the result of the interaction of the activity of the prefrontal cortex and emotional centers, as the most important pathogenetic link in the psychosomatic relations of depressive and cardiovascular diseases. The neuroanatomical substrate of emotional regulation is the connection between emotional and cognitive processes, which are carried out through bidirectional neuronal interactions between the neocortex and emotional centers. This connection allows emotional centers to modulate cortical activity, and cognitive centers, through descending cortical influences, to modulate the processing of emotions. At present, direct and indirect connections of the frontal cortex with the centers of the autonomic nervous system and its stimulating sympathetic and inhibitory parasympathetic influences have been confirmed. Pathogenetic links of emotional dysregulation include neurobiological and cognitive (rumination, fixation on negative information) processes. The pathophysiological mechanisms of depression and cardiovascular diseases have common links - the dysregulation of the metabolic, immunological and hypothalamus-pituitary-adrenal systems. The tendency to negative emotional response, the prevalence of negative emotions and alexithymia (low awareness of emotions) stand out as predictors of the development of both cardiovascular diseases and depression. Studies aimed at studying the typology and meaning of emotional dysregulation in various forms of psychopathological disorders in the aspect of comorbidity and psychosomatic relationships with somatic diseases can be fruitful in terms of finding new approaches to diagnosis and therapy

Emergence of Coordinated Activity in the Developing Entorhinal–Hippocampal Network

International audienceCorrelated activity in the entorhinal-hippocampal neuronal networks, supported by oscillatory and intermittent population activity patterns is critical for learning and memory. However, when and how correlated activity emerges in these networks during development remains largely unknown. Here, we found that during the first postnatal week in non-anaesthetized head-restrained rats, activity in the superficial layers of the medial entorhinal cortex (MEC) and hippocampus was highly correlated, with intermittent population bursts in the MEC followed by early sharp waves (eSPWs) in the hippocampus. Neurons in the superficial MEC layers fired before neurons in the dentate gyrus, CA3 and CA1. eSPW current-source density profiles indicated that perforant/temporoammonic entorhinal inputs and intrinsic hippocampal connections are co-activated during entorhinal-hippocampal activity bursts. Finally, a majority of the entorhinal-hippocampal bursts were triggered by spontaneous myoclonic body movements, characteristic of the neonatal period. Thus, during the neonatal period, activity in the entorhinal cortex (EC) and hippocampus is highly synchronous, with the EC leading hippocampal activation. We propose that such correlated activity is embedded into a large-scale bottom-up circuit that processes somatosensory feedback resulting from neonatal movements, and that it is likely to instruct the development of connections between neocortex and hippocampus