IMBICE   05372
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA CELULAR
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Cold exposure activates Thyrotropin Releasing Hormone (TRH)-producing neurons in specific brain nuclei
Autor/es:
SPRING VALDIVIA; AGUSTINA CABRAL; MIRTA REYNALDO; SILVIA GORDON; YAMILA QUIROGA; EDUARDO A. NILLNI; MARIO PERELLO
Reunión:
Congreso; XXVI Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia; 2011
Resumen:
TRH mediates cold-induced thermogenesis via both
neuroendocrine and autonomic mechanisms. It is known that the TRH neurons
located in the hypothalamic paraventricular nucleus (PVN) regulate the
neuroendocrine thyroid axis. In contrast, what populations of TRH neurons mediate
the activation of the sympathetic mechanisms induced by cold exposure is
unclear. Here, we systematically examined the distribution of TRH neurons
activated in response to cold exposure throughout the adult rat brain. To map
the activation TRH neurons, we used double immunohistochemistry for the marker
of cellular activation, cfos, and the TRH prohormone. To further assess the
functional consequences of the cfos expression in TRH neurons, we evaluated the
preproTRH mRNA levels in brain micro-dissections where TRH is produced. Our
analysis was focused on hypothalamic regions including the PVN, the pre-optic
area, dorsomedial nucleus and the lateral hypothalamus, and areas of the
medulla including raphe obscurus,
raphe pallidus (RPa) and
parapyramidal regions. Our data indicated that only the TRH neurons located in
the PVN and the RPa are activated in animals exposed to cold. Thus, these
groups of TRH neurons are the main candidates participating in cold-induced
thermogenic mechanisms.