Effects of acetylcholine and cholinolytics on the synaptic transmission in the ampullae of Lorenzini of the skate

Pharmacology and Neurotransmission of Sensory Transduction in the Inner Ear

“…Therefore, it was postulated that ACh and carbachol act presynaptically to induce the release of the afferent transmitter. Similar findings and conclusions have been reported by Akoev et al (1983) in the Lorenzinian ampullae of the skate. In addition, Bernard et al (1985) have reported that cholinergic agonists and electrical stimulation of efferents increase the spontaneous discharge rate of the afferent nerve in the in vitro frog sem-128 icircular canal.…”

Synaptic Transmission in the Mechano- and Electroreceptors of the Acousticolateral System

“…One may suppose that perfusion with a solution containing ACh results in depolarization of the presynaptic membrane and thus the amount of endogenous transmitter release increases. The cholinolytic agents atropine and d-tubocurarine did not block the synaptic transmission (Akoev et al 1983) and had no influence on the amplitude of EPSP in the Lorenzinian ampullae (Steinbach 1974). So, ACh is unlikely to be the afferent transmitter in receptors of the acousticolateral system.…”

“…Effect of saline containing 5 x 10-4 MACh on the resting firing rate of an afferent fiber of the ampullae of Lorenzini in Mg;+ -rich solution. (Akoev et al 1983) curarine influenced the spontaneous activity of electroreceptors in transparent catfish (Teeter and Bennett 1981) and the marine catfish Plotosus (Bennett and Obara 1986). The effect of ACh and cholinolytics on the synaptic processes in the ampullae of Lorenzini of skates has also been investigated (Akoev et al 1983).…”

“…(Akoev et al 1983) curarine influenced the spontaneous activity of electroreceptors in transparent catfish (Teeter and Bennett 1981) and the marine catfish Plotosus (Bennett and Obara 1986). The effect of ACh and cholinolytics on the synaptic processes in the ampullae of Lorenzini of skates has also been investigated (Akoev et al 1983). ACh exerted a strong excitatory effect on the ampullae of Lorenzini; however, these effects were not related to its action on the postsynaptic membrane, since when the synaptic transmission was blocked with a Mg2+ -rich solution, ACh did not induce impulse activity in the afferent fibers (Fig.…”