Discharge properties of neurons recorded in the parvalbumin-positive (PV1) nucleus of the rat lateral hypothalamus

Abstract

h i g h l i g h t s• Random-like firing characterized the majority of PV1 cells.• Oscillations in the delta range were observed in the posterior part of PV1 nucleus.• The asynchronous activity produces a network-driven effect on the PV1-target area.This study reports for the first time the extracellular activity recorded, in anesthetized rats, from cells located in an identified cluster of parvalbumin (PV)-positive neurons of the lateral hypothalamus forming the PV1-nucleus. Random-like firing characterized the majority (21/30) of the cells, termed regular cells, with a median firing rate of 1.7 spikes/s, Fano factor equal to 1, and evenly distributed along the rostrocaudal axis. Four cells exhibiting an oscillatory activity in the range 1.6-2.1 Hz were observed only in the posterior part of the PV1-nucleus. The asynchronous activity of PV1 neurons is likely to produce a "network-driven" effect on their main target within the periaqueductal gray matter. The hypothesis is raised that background random-like firing of PV1-nucleus is associated with functional network activity likely to contribute dynamic information related to condition transitions of awareness and non-conscious perception.

Complex temporal patterns processing by a neural mass model of a cortical column

“…In particular, the GABAergic (PV)-positive neurons play a key role in regulating synchronous activity observed in the thalamocortical circuit (Carle ´n et al 2012;Albe ´ri et al 2013;Lintas et al 2013;Gruart et al 2016). Long-range projecting GABAergic PV-expressing neurons in the neocortex (Lee et al 2014) and hypothalamus (Lintas 2014) further emphasize inhibitory synaptic plasticity as an attractive candidate mechanism for controlling the dynamic state of cortical networks involved in gating transitions of awareness and non-conscious perception.…”

Electrophysiological properties and projections of lateral hypothalamic parvalbumin positive neurons

“…Our single-cell RT-qPCR analysis demonstrates that LH PV neurons are equipped with ion channels that are implicated in setting and regulating fast-spiking activity [ 12 ]. Interestingly, heterogeneous firing patterns were observed in a preliminary study attempting to record spontaneous activity from LH PV neurons extracellularly in anaesthetized rats [ 28 ]. However, these experiments were performed with traditional extracellular electrophysiology methods in which an intrinsic limitation is the accurate identification of the recorded cell types.…”

The different effects of high-frequency stimulation of the nucleus accumbens shell and core on food consumption are possibly associated with different neural responses in the lateral hypothalamic area

“…The LHA neurons were identified by their classically defined electrophysiological characteristics ( Fig. 2) (Li et al, 2013;Lintas, 2014). Only stable discharges with a signal-to-noise ratio >3:1 that corresponded to spikes were recorded.…”

“…Three firing types of the LHA cells were identified by the analysis of the autocorrelograms (Hu et al, 2011;Lintas, 2014) and the characteristics of the waveform of the spikes. The first type was marked by a regular firing rhythm (RFR) and wide waveform (PVT: 0.569 ± 0.013 ms; HDT: 0.563 ± 0.016 ms), referred to as a RFR cell type.…”

“…5). The FF value was used to distinguish excitatory and inhibitory neurons in neural networks in previous papers (Becchetti et al, 2012;Lintas, 2014). Inhibitory neurons typically had a higher FF value and a thin waveform; thus, we could regard BFR neurons as inhibitory neurons in the neural networks.…”