Biology subjects

Fisone, G.

Publications and source records attributed to Fisone, G..

5 recordsLinked to original sources

bioRxiv2026

DARPP-32 in motor cortex regulates structural and synaptic plasticity in corticothalamic neurons and enables motor learning.

The dopamine and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32), a key mediator of monoaminergic signaling, is expressed in the cortex; however, its cellular distribution and role in cortically dependent behaviors remain elusive. Here, we determined the functional integration of DARPP-32 in motor cortex circuitry using molecular profiling, circuit tracing, patch-clamp electrophysiology, virus-assisted gene targeting and motor behavior analyses. Unlike the significant overlap between DARPP-32 and dopamine receptors in striatal GABAergic medium spiny projection neurons, we found that the majority of DARPP-32-positive cortical neurons express the corticothalamic marker FoxP2 but not dopamine D1 or D2 receptors. Notably, in cortical slices, adenylyl cyclase activation induced a more robust increase in DARPP-32 phosphorylation at threonine 34, a protein kinase A target site, compared to dopamine D1 receptor stimulation. Conditional ablation of DARPP-32 in the motor cortex did not affect basal or psychostimulant-induced motor activity but reduced motor aptitude and compromised overnight retention of motor skill. Concomitantly, the absence of DARPP-32 reduced dendritic spines density and prevented the induction of glutamatergic long-term potentiation in layer 6 motor cortical neurons. Altogether, our study demonstrates a critical role for DARPP-32 in cortical synaptic plasticity, emphasizing its importance in corticothalamic regulation of motor skill learning.

neuroscience↗

bioRxiv2025

A subset of dorsal raphe dopamine neurons is critical for survival-oriented vigilance.

Defensive behaviors are essential for survival, with risk assessment enabling organisms to evaluate and respond to potential threats. The dorsal raphe nucleus (DRN), a key neuromodulatory center, is crucial for encoding motivational salience and regulating arousal and sleep-wake states through its diverse neuronal populations, including dopaminergic neurons (DRNDA). While the roles of DRNDA neurons have been studied, their specific contributions to threat evaluation are less understood. Recent research identifies a distinct subset of DRNDA neurons that express vasoactive intestinal peptide (VIP) and project to the central amygdala (CeA) and the oval nucleus of the bed nucleus of the stria terminalis (ovBNST). Together, these two regions comprise the central extended amygdala, a key network regulating adaptive responses to threats. We hypothesized that distinct DRNDA subpopulations exert diverging effects on sleep-wake regulation and that DRNVIP neurons play a pivotal role in coordinating activity between the CeA and ovBNST, thereby influencing risk assessment and defensive response. To test this hypothesis, we used a combination of in situ hybridization, immunochemistry, whole-brain mapping, electrophysiology, and cell-specific genetic tools in mice and non-human primates. Our findings reveal that DRNVIP neurons form a key DRNDA neuronal subset, uniquely positioned to regulate the central extended amygdala through a feedback loop. These neurons receive inputs from Protein Kinase C delta (PKC-{delta}) neurons in the ovBNST and CeA and send glutamate-releasing projections back to these regions, modulating PKC-{delta} neuron excitability. Selective ablation of DRNVIP neurons increases activity in both the BNST and CeA, disrupting active-phase sleep architecture and impairing risk assessment and defensive behaviors. Together, these findings suggest DRNVIP neurons control specific phases of sleep and orchestrate the central extended amygdalas role in risk assessment and defensive responses. HIGHLIGHTSO_LIDRNVIP neurons form a subset of DRNDA neurons in mice and non-human primates. C_LIO_LIDRNVIP receive inputs from Protein Kinase C delta (PKC-{delta}) neurons in the ovBNST and CeA and project back to both. C_LIO_LIBy releasing glutamate, DRNVIP neurons regulate PKC-{delta} neuron excitability in the ovBNST and CeA. C_LIO_LIAblating DRNVIP neurons increases BNST and CeA activity, disrupts active-phase sleep architecture, and impairs threat responses. C_LI IN BRIEFDRNVIP neurons, a key subset of DRNDA neurons in mice and primates, are strategically positioned to influence the central extended amygdala via feedback loops. They regulate PKC-{delta} neuron excitability in the ovBNST and CeA through glutamate release, with their ablation heightening activity in these regions and altering active-phase sleep architecture, risk assessment and defensive behaviors.

neuroscience↗

bioRxiv2023

Serotonergic and dopaminergic neurons in the dorsal raphe are differentially altered in a mouse model for Parkinson's disease.

Parkinsons disease (PD) is characterized by motor impairments caused by degeneration of dopamine neurons in the substantia nigra pars compacta. In addition to these symptoms, PD patients often suffer from non-motor co-morbidities including sleep and psychiatric disturbances, which are thought to depend on concomitant alterations of serotonergic and noradrenergic transmission. A primary locus of serotonergic neurons is the dorsal raphe nucleus (DRN), providing brain-wide serotonergic input. Here, we identified electrophysiological and morphological parameters to classify serotonergic and dopaminergic neurons in the murine DRN under control conditions and in a PD model, following striatal injection of the catecholamine toxin, 6-hydroxydopamine (6-OHDA). Electrical and morphological properties of both neuronal populations were altered by 6-OHDA. In serotonergic neurons, most changes were reversed when 6-OHDA was injected in combination with desipramine, a noradrenaline reuptake inhibitor, protecting the noradrenergic terminals. Our results show that the depletion of both noradrenaline and dopamine in the 6-OHDA mouse model causes changes in the DRN neural circuitry.

neuroscience↗

bioRxiv2023

Maternal hormones engage a dormant monomorphic aggression circuit, leading to the introduction of an innate behavior in adulthood in females

Aggression, a sexually dimorphic behaviour, is prevalent in males and typically absent in virgin females. Following parturition, however, the transient expression of aggression in adult female mice protects pups from predators and infanticide by male conspecifics. While maternal hormones are known to elicit nursing, their potential role in maternal aggression remains elusive. Here, we show in mice that a molecularly defined subset of ventral premammillary (PMvDAT) neurons, instrumental for intermale aggression, switch from quiescence to a hyperexcitable state during lactation. We identify that the maternal hormones prolactin and oxytocin excite these cells through actions that include T-type Ca2+ channels. Optogenetic manipulation or genetic ablation of PMvDAT neurons profoundly affects maternal aggression, while activation of these neurons impairs the expression of non-aggression-related maternal behaviours. This work identifies a monomorphic neural substrate that can incorporate hormonal cues to enable the transient expression of a dormant behavioural program in lactating females.

neuroscience↗

bioRxiv2022

Haloperidol-induced immediate early genes in striatopallidal neurons requires the converging activation of cAMP/PKA/DARPP-32 and mTOR pathways

Antipsychotics share the common pharmacological feature of antagonizing the dopamine 2 receptor (D2R) which is abundant in the striatum and involved in both the therapeutic and side effects of this drugs class. Pharmacological blockade of striatal D2R, by disinhibiting the D2R-containing medium-size spiny neurons (MSNs), leads to a plethora of molecular, cellular and behavioral adaptations which are central in the action of antipsychotics. Here, we focused on the cell type-specific (D2R-MSNs) regulation of some striatal immediate early genes (IEGs), such as cFos, Arc and Zif268. Taking advantage of transgenic mouse models, pharmacological approaches and immunofluorescence analyses, we found that haloperidol-induced IEGs in the striatum required the synergistic activation of A2a (adenosine) and NMDA (glutamate) receptors. At the intracellular signaling level, we found that the PKA/DARPP-32 and mTOR pathways synergistically cooperate to control the induction of IEGs by haloperidol. By confirming and further expanding previous observations, our results provide novel insights into the regulatory mechanisms underlying the molecular/cellular action of antipsychotics in the striatum.

neuroscience↗