Two forms of sensitization of the local bending reflex of the medicinal leech.
Research article published in Journal of comparative physiology. A, Sensory, neural, and behavioral physiology (1991)
Abstract
Sensitization of the local bending reflex of the medicinal leech Hirudo medicinalis was studied in a semi-intact preparation in which behavioral and electrophysiological recordings were made simultaneously. 1. Sensitization of local bending could be produced in two ways: by repeated stimulation of the mechanoreceptor sensitive to pressure (the P cell), and by stimulation of the mechanoreceptor sensitive to noxious stimuli (the N cell). 2. Both forms of sensitization produced a central neuronal change, measured as an increase in the number of stimulus-evoked action potentials in cell 3 (an excitor of dorsal longitudinal muscles). 3. Intracellular stimulation of serotonin-containing neurons 21 and 61 mimicked the sensitizing stimuli, but stimulation of the Retzius cell, which also contains serotonin, did not. 4. Stimulation of the Leydig cell, which releases octopamine, decreased the strength of local bending.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Two forms of sensitization of the local bending reflex of the medicinal leech.
Why This Matters for Hirudotherapy
This study examined sensitization of the local bending reflex in the medicinal leech Hirudo medicinalis using a semi-intact preparation with simultaneous behavioral and electrophysiological recordings. The investigators found that sensitization could be produced in two ways: by repeated stimulation of pressure-sensitive P cells, and by stimulation of noxious-stimulus-sensitive N cells, with both forms producing a central neuronal change measured as increased action potentials in cell 3. For ASH and hirudotherapy, this work contributes to understanding the fundamental neurobiology and behavior of Hirudo medicinalis, the species central to medicinal leech therapy, though it does not directly address the therapeutic secretome or clinical outcomes of leech therapy. The study is basic neurophysiological research and has no direct implications for leech therapy practice.
Citation
Two forms of sensitization of the local bending reflex of the medicinal leech.
Lockery et al. · Journal of comparative physiology. A, Sensory, neural, and behavioral physiology, 1991
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