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Several molecules have been proposed as excitatory transmitters between glomus (type 1) cells and nerve terminals of petrosal ganglion (PG) neurons in the carotid body (CB). We tested whether ACh and ATP have a role to play as excitatory transmitters in the cat CB by recording intracellularly from identified PG neurons functionally connected to the CB in(More)
The carotid body (CB) is the main arterial chemoreceptor. The most accepted model of arterial chemoreception postulates that carotid body glomus (type I) cells are the primary receptors, which are synaptically connected to the nerve terminals of petrosal ganglion (PG) neurons. In response to natural stimuli, glomus cells are expected to release one (or(More)
Hypoxia modulates proliferation and differentiation of cultured embryonic and adult stem cells, an effect that includes β-catenin, a key component of the canonical Wnt signaling pathway. Here we studied the effect of mild hypoxia on the activity of the Wnt/β-catenin signaling pathway in the hippocampus of adult mice in vivo. The hypoxia-inducible(More)
Chronic intermittent hypoxia (CIH) enhances carotid body (CB) chemosensory responses to acute hypoxia. We tested the hypothesis that endothelin-1 (ET-1), an excitatory modulator of CB chemoreception may contribute to the enhanced CB chemosensory responses in cats exposed to cyclic hypoxic episodes repeated during 8 h for 4 days. Accordingly, we measured the(More)
Chemoreceptor (glomus) cells of the carotid body are synaptically connected to the sensory nerve endings of petrosal ganglion (PG) neurons. In response to natural stimuli, the glomus cells release transmitters, which acting on the nerve terminals of petrosal neurons increases the chemosensory afferent discharge. Among several transmitter molecules present(More)
Patients with obstructive sleep apnea (OSA) show augmented ventilatory, sympathetic and cardiovascular responses to hypoxia. The facilitatory effect of chronic intermittent hypoxia (CIH) on the hypoxic ventilatory response has been attributed to a potentiation of the carotid body (CB) chemosensory response to hypoxia. However, it is a matter of debate(More)
1. To examine the correlation between chemosensory response and dopamine release induced by hypoxic stimulation, we studied carotid bodies excised from anaesthetized cats. 2. The carotid bodies with their carotid (sinus) nerves were superfused in vitro with modified Tyrode solution (pH 7.40, at 37.5 degrees C) equilibrated with 20 or 100% O2. The PO2 of the(More)
Petrosal ganglion neurons are depolarized and fire action potentials in response to acetylcholine and nicotine. However, little is known about the subtype(s) of nicotinic acetylcholine receptors involved, although alpha4 and alpha7 subunits have been identified in petrosal ganglion neurons. Cytisine, an alkaloid unrelated to nicotine, and its bromo(More)
The membrane potential hypothesis that the responses to hypercapnia of carotid chemosensory activity is mediated by voltage-gated Ca2+ channels was investigated by measuring directly the chemosensory output from rat and cat carotid bodies, perfused and superfused in vitro. We found that the inorganic and organic blockers of voltage-gated Ca2+ channels(More)
The present work was aimed to evaluate the contribution of interoception to the autonomic and behavioral responses to hypoxia. To address this issue, we studied whether the inactivation of the primary interoceptive posterior insular cortex (pIC) may disrupt the autonomic and behavioral effects of hypoxia in conscious rats. Rats were implanted with(More)