LEPTIN ALTERS SOMATOSENSORY THALAMIC INHIBITORY SYNAPTIC TRANSMISSION

BISAGNO V; PERISSINOTTI PP; URBANO FJ; GARCIA-RILL E

Congreso; FALAN 2016; 2016

Leptin is an adipose-derived hormone that circulates in the plasma at levels correlated with body fat mass. The best known role of leptin focus on energy balance in the hypothalamus, but extra-hypothalamic brain regions also express leptin receptors. Obesity is characterized by disrupted sleep architecture and wake disturbances. Arousal and rapid eye movement sleep are modulated by the cholinergic arm of the reticular activating system, the pedunculopontine nucleus (PPN) and its ascending thalamocortical targets. Since leptin has an overall inhibitory effect on the PPN neurons activity, we continue studying its effects on the somatosensory thalamic activity. Inhibitory postsynaptic currents (IPSC) were evoked by extracellular 10 Hz paired-pulse stimulation of reticular afferents to ventrobasal (VB) neurons in brain slices from wildtype (WT) or the leptin-deficient mice (ob/ob). Local application of leptin reversibly reduced the amplitude of the first IPSC by 40% and enhanced GABA release probability from WT (n=6 VB) but not ob/ob mice (n=7 VB; ANOVA P