Biology subjects

Grinevich, V.

Publications and source records attributed to Grinevich, V..

21 records · Page 2Linked to original sources

bioRxiv2020

Concerted but segregated actions of oxytocin and vasopressin within the ventral and dorsal lateral septum determine female aggression

In contrast to males, aggression in females has been rarely studied. Here, we established a rat model of enhanced female aggression using a combination of social isolation and aggression-training to specifically investigate the involvement of the oxytocin (OXT) and vasopressin (AVP) systems within the lateral septum (LS). Using neuropharmacological, optogenetic, chemogenetic as well as microdialyses approaches, we revealed that enhanced OXT release within the ventral LS (vLS), combined with reduced AVP release within the dorsal LS (dLS), are required for female aggression. Accordingly, increased excitability of OXT-responsive neurons in the vLS and decreased excitability of AVP-responsive neurons in the dLS were essential to evoke female aggression. Finally, in vitro activation of OXT receptors in the vLS increased tonic GABAergic inhibition of dLS neurons. Overall, our data demonstrate that septal release of OXT and AVP affects female aggression by differential regulation of the excitatory-inhibitory balance within subnetworks of the LS.

neuroscience↗

bioRxiv2020

Extra-hypothalamic oxytocin neurons drive stress-induced social vigilance and avoidance

Oxytocin increases the salience of both positive and negative social contexts and it is thought that these diverse actions on behavior are mediated in part through circuit-specific action. This hypothesis is based primarily on manipulations of oxytocin receptor function, leaving open the question of whether different populations of oxytocin neurons mediate different effects on behavior. Here we inhibited oxytocin synthesis in a social stress-sensitive population of oxytocin neurons specifically within the medioventral bed nucleus of the stria terminalis (BNSTmv). Oxytocin knock-down prevented stress-induced increases in social vigilance and decreases in social approach. Viral tracing of BNSTmv oxytocin neurons revealed fibers in regions controlling defensive behaviors including lateral hypothalamus, anterior hypothalamus, and anteromedial BNST (BNSTam). Oxytocin infusion into BNSTam in stress naive mice increased social vigilance and reduced social approach. These results show that a population of extra-hypothalamic oxytocin neurons play a key role in controlling stress-induced social anxiety behaviors.

neuroscience↗

bioRxiv2020

Oxytocin Acts on Astrocytes in the Central Amygdala to Promote a Positive Emotional State

Oxytocin orchestrates social and emotional behaviors through modulation of neural circuits in brain structures such as the central amygdala (CeA). The long-standing dogma is that oxytocin signaling in the central nervous system occurs exclusively via direct actions on neurons. However, several findings over the last decades showed that astrocytes actively participate in the modulation of neuronal circuits. Here, we investigate the degree of astrocytes involvement in oxytocin functions. Using astrocyte specific gain and loss of function approaches, we demonstrate that CeA astrocytes not only directly respond to oxytocin, but are actually necessary for its effects on neuronal circuits and ultimately behavior. Our work identifies astrocytes as a crucial cellular substrate underlying the promotion of a positive emotional state by oxytocin. These results further corroborate that astrocytes are key regulators of neuronal circuits activity by responding to specific neuropeptidergic inputs, and opens up new perspectives to understand how neuromodulators gate brain functions.

neuroscience↗