Fig. 4: Thermoafferent LPBN pathway is required to trigger heat acclimation.
From: Thermally induced neuronal plasticity in the hypothalamus mediates heat tolerance
a, Schematic showing the viral injection strategy for TeTxLC-mediated silencing of excitatory (Vglut2-positive) presynaptic neurons located in the LPBN and innervating VMPO. b, Example images showing the expression of AAV-FRT-TeTxLC-EGFP (green) and retroAAV-dlox-FlpO-mCherry (red) in the VMPO (left) and in VMPO-projecting LPBN neurons (right). Scale bars, 250 μm. The histological labeling confirmed double infection of glutamatergic LPBN neurons in Vglut2-Cre mice expressing the recombinase FlpO (red; derived from the retroAAV injected into VMPO) and TeTxLC (green; derived from Cre- and FlpO-dependent AAV particles injected into the LPBN) (middle). Scale bar, 100 μm. Note that labeled neurons are mainly located in the dorsal lateral part of the LPBN; no TeTxLC is detectable in the POA (top left), assuring that inhibition happened at the level of the LPBN but not the POA. c, Body temperature traces of individual LPBN → VMPO silenced (Cre-positive, green, N = 5) and nonsilenced control (Cre-negative, gray, N = 5) animals during the initial 48 h of heat acclimation. In contrast to Cre-negative animals, all animals expressing TeTxLC failed to maintain their body temperature <41.5 °C during the first 2 d of acclimation (Extended Data Figs. 6 and 7).
