Artículo de revista
ATP- and ACh-induced responses in isolated cat petrosal ganglion neurons
Fecha
2007-02Registro en:
Volume: 1131, Issue: 1, pag.: 60-67, 2007
0006-8993
Autor
Alcayaga, Carmen
Varas, Rodrigo
Valdés, Viviana
Cerpa, Verónica
Arroyo, Jorge
Iturriaga, Rodrigo
Alcayaga Urbina, Julio
Institución
Resumen
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 in
glomus cells, acetylcholine (ACh) and adenosine 5′-triphosphate (ATP) are considered to act
as excitatory transmitter in this synapse. To test if ACh and ATP play a role as excitatory
transmitters in the cat CB, we recorded the electrophysiological responses from PG neurons
cultured in vitro. Under voltage clamp, ATP induces a concentration-dependent inward
current that partially desensitizes during 20–30 s application pulses. The ATP-induced
current has a threshold near 100 nM and saturates between 20–50 μM. ACh induces a fast,
inactivating inward current, with a threshold between 10–50 μM, and saturates around
1 mM. A large part of the population of PG neurons (60%) respond to both ATP and ACh.
Present results support the hypothesis that ACh and ATP act as excitatory transmitters
between cat glomus cells and PG neurons.