Synaptic integration at a sensory-motor reflex in the leech

X. Gu, Kenneth J Muller, S. R. Young

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

1. In the medicinal leech the distribution of synapses from the pressure sensory (P) neurone to the annulus erector (AE) motoneurone and the site of impulse initiation in the AE cell were determined to understand better the integration of sensory inputs by the motoneurone. 2. The axon of the AE cell bifurcates before leaving the ganglion. Laser photoablation experiments indicated that the axon proximal to the bifurcation is inexcitable. Two techniques, laser photoablation and measurement of impulse timing, each located the site of impulse initiation at the bifurcation. 3. The medial P cell makes a monosynaptic connection with the AE cell, eliciting an excitatory postsynaptic potential (EPSP) of 1-3 mV amplitude recorded in the AE cell soma. 4. Intracellular injection of dyes into separate cells showed that P cell branches appear to contact AE cell branches both ipsilaterally and contralaterally. Laser photoablation of selected portions of the P and AE cells' axons revealed functional contacts on both sides. 5. The primary axon bifurcation of the AE cell is the site of integration of synaptic potentials that spread passively from both sides of the ganglion. These summed synaptic potentials account for the concerted activity of the two AE cells in each ganglion.

Original languageEnglish
Pages (from-to)733-754
Number of pages22
JournalJournal of Physiology
Volume441
StatePublished - Jan 1 1991

Fingerprint

Leeches
Reflex
Axons
Ganglia
Synaptic Potentials
Lasers
Motor Neurons
Excitatory Postsynaptic Potentials
Carisoprodol
Sensory Receptor Cells
Synapses
Coloring Agents

ASJC Scopus subject areas

  • Physiology

Cite this

Synaptic integration at a sensory-motor reflex in the leech. / Gu, X.; Muller, Kenneth J; Young, S. R.

In: Journal of Physiology, Vol. 441, 01.01.1991, p. 733-754.

Research output: Contribution to journalArticle

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