Memory in the Hirudo Medicinalis retzius cell: spiking rate as function of past membrane potential
نویسندگان
چکیده
Dramatic advances in electrophysiological technologies combined with the resilience of leech preparation have made experimental neuroscience accessible to the classroom. The Retzius cell in Hirudo Medicinalis is a prime target for current-dependent frequency studies. Fundamental spiking dynamics were explored in Retzius by examining short term memory effects of voltage clamping. Two successive voltages were clamped for half second or full second intervals. Activity during the second phase was monitored for dependence on the previous phase. Experimental results of this assay revealed noticeable memory effects in cellular activity. In addition, memory was found to be influenced by the substitution of isoelectric Ba for Ca in extracellular solution. This study is an investigation of action potential dynamics unaccounted for by the Hodgkin-Huxley model and is potentially illuminating on the cellular dynamics of Retzius in Hirudo Medicinalis.
منابع مشابه
An increase in activity of serotonergic Retzius neurones may not be necessary for the consummatory phase of feeding in the leech Hirudo medicinalis.
During the consummatory phase of feeding, in which blood is ingested, medicinal leeches display a characteristic set of behaviours: they extend their jaws, are less responsive to sensory input, produce mucus, relax the body wall and exhibit waves of peristalsis that can run the length of the body. Earlier reports suggested that this pattern of behaviour is orchestrated by serotonin released fro...
متن کاملNeuron-silicon junction with voltage-gated ionic currents.
We recorded the signals of firing Retzius neurons from Hirudo medicinalis by field-effect transistors. The axon stump of dissociated cells was attached to an open gate coated with concanavalin A. We observed a new type of neuron-transistor coupling: the extracellular voltage transients beneath the neuron were dominated by a negative peak during the rising phase of the action potential with a we...
متن کاملCoactivation of putative octopamine- and serotonin-containing interneurons in the medicinal leech.
Possible interactions between octopamine-immunoreactive (IR) and serotonergic neurons in the CNS of the medicinal leech were investigated. Simultaneous intracellular recordings of serotonin-containing neurons (either the Retzius neuron or cell 21) and the dorsolateral octopamine-IR (DLO) neuron demonstrated that both sets of neurons are coactive at times. Depolarization of either serotonergic c...
متن کاملDevelopment of serotonin-induced ion currents in identified embryonic Retzius cells from the medicinal leech (Hirudo medicinalis).
Retzius cells and the cutaneous baroreceptive P-cells of adult medicinal leeches (Hirudo medicinalis) respond to 5-HT by Cl- as well as by monovalent cation conductances (Drapeau et al., 1989). However, chemical synaptic connections between Retzius cells (Liu and Nicholls, 1989) as well as Retzius cells and P-cells in culture (Drapeau and Sanchez-Armass, 1988) are mediated by postsynaptic Cl- c...
متن کاملThe action of acetylcholine, dopamine and 5-hydroxytryptamine on the spontaneous activity of the cells of Retzius of the leech, Hirudo medicinalis.
Neuropharmacological and neurophysiological studies have been undertaken on both the longitudinal muscle and on the segmental ganglionic neurones of the leech, Hirudo medicinalis. The longitudinal muscle of the leech was developed by Minz (1932) from the initial observations of Fuehner (1918) as an assay procedure for acetylcholine. More recently this same preparation has been used as an assay ...
متن کامل