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Proceedings of the 2018 SfN Neuroscience - CRF neurons in the paraventricular thalamus reduce food-seeking behavior

Congreso

Autoría:

Terzian, A.B. ; Engelke, D.S. ; Naim-Rasheed, Maria ; Li, S. ; O'Malley, J. ; Dasgupta, R. ; FERNANDEZ LEON, JOSE ALBERTO ; Justice, N. ; Beierlein, M. ; Kirouac, G.J. ; Do-Monte, F.H.

Fecha:

2018

Editorial y Lugar de Edición:

SfN Neuroscience

Resumen *

The paraventricular nucleus of the thalamus (PVT) regulates behavioral responses under emotionally arousing conditions. Photoactivation of anterior PVT (aPVT) neurons abolishes sucrose seeking and induces aversive behaviors in rodents. However, the specific aPVT neuronal subpopulation regulating these functions remains unknown. The stress neuropeptide corticotropin‐releasing factor (CRF) has been shown to reduce food intake and induce anxiety-like behavior in different species. Interestingly, a recent neuroanatomical study demonstrated that CRF neurons are present in the aPVT, but their physiological functions have never been explored. To assess the role of aPVT-CRF neurons during sucrose seeking, adult male Long-Evans rats were infused with a mixture of viral vectors (AAV-CRF-Cre and AAV-ChR2-DIO-eYFP) to express channelrhodopsin in aPVT-CRF neurons. Animals were trained in a reward conditioning task, where each bar press during a 30s cue tone delivered a sugar pellet in a nearby dish. High-frequency photoactivation of aPVT CRF neurons (20 Hz, 5ms pulse width, 10 mW) during the cue tone reduced bar presses when compared to the eYFP-Control group (aPVT-CRF-ChR2, presses/min: Laser OFF: 14.5±1.4, Laser ON: 4.2±1.1; eYFP-Control, presses/min: Laser OFF: 17.5±1.1, Laser ON: 18.8±1.2, p<0.05). In contrast, 5Hz low-frequency photoactivation of aPVT-CRF neurons had no effect (aPVT-CRF-ChR2, presses/min: Laser OFF: 17.2±0.9, Laser ON: 14.88±1.6, p=0.20). Photoactivation of aPVT-CRF neurons also reduced the time spent on the side of the chamber paired with 20Hz laser stimulation in a real-time place preference task, indicating that stimulation of aPVT-CRF neurons is aversive (Laser OFF side: 80.7%, Laser ON side: 19.2%, p<0.05). Neuroanatomical investigation of aPVT-CRF efferents revealed dense projections to the nucleus accumbens shell (NAc-shell); moderate projections to the nucleus accumbens core, lateral region of the bed nucleus of the stria terminalis, lateral subnuclei of the central nucleus of the amygdala and suprachiasmatic nucleus; and relatively weak projections to the infralimbic/prelimbic cortex, basolateral nucleus of the amygdala, and medial regions of the hypothalamus. Slice recordings from NAc-shell neurons demonstrated that photoactivation of aPVT-CRF fibers in the NAc-shell elicits large excitatory postsynaptic responses, which are blocked by AMPA and NMDA receptor antagonists. Our results demonstrate the existence of a defined glutamatergic-CRF-expressing subpopulation of neurons in aPVT that is sufficient to mediate anorexigenic and aversive effects in rats. Información suministrada por el agente en SIGEVA

Palabras Clave

CRF neuronsFood seekingParaventricular thalamus