TY - JOUR
T1 - The appearance and development of neurotransmitter sensitivity in Xenopus embryonic spinal neurones in vitro.
AU - Bixby, J. L.
AU - Spitzer, N. C.
N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.
PY - 1984/8/1
Y1 - 1984/8/1
N2 - 1. We have determined the time of onset and examined some of the properties of neurotransmitter sensitivity in Xenopus spinal neurones developing is dissociated cell culture. These cells are initially insensitive, but acquire responses to several agonists over a period of 6 h. 2. Nearly one-third of the neurones were depolarized by γ-aminobutyric acid (GABA) or by both GABA and glycine; these cells were not affected by glutamate. The reversal potential of the ionophoretic GABA response is -35 mV. These neurones are likely to be Rohon-Beard neurones. Roughly two-thirds of the neurones were depolarized by glutamate and hyperpolarized by GABA and by glycine. The reversal potential of the ionophoretic GABA response in -58 mV. These neurones are likely to include motoneurones. 3. A quantitative measure of the sensitivity to a given GABA dose was obtained at early and intermediate stages of development. The mean 'sensitivity index' (ionophoretic sensitivity/input resistance) for both classes of neurones in vitro was initially the same as that seen in Rohon-Beard neurones in vivo. This sensitivity index did not increase with time in culture to attain the value at intermediate stages in vivo. 4. The development of chemosensitivity in Rohon-Beard-like neurones in these cultures resembles that of Rohon-Beard neurones in the spinal cord with respect to the time of onset of response to GABA, the reversal potential, pharmacology and desensitization of these responses, and the spectrum of agonists to which they are sensitive. It differs in the absence of a developmental increase in sensitivity to GABA. The development of chemosensitivity in motoneurone-like neurones in these cultures parallels that of Rohon-Beard-like neurones, with respect to the time of onset and level of sensitivity, as well as susceptibility to pharmacological blockers. 5. Several features of normal neurotransmitter sensitivity, like features of the action potential, differentiate in culture in the absence of normal cellular interactions.
AB - 1. We have determined the time of onset and examined some of the properties of neurotransmitter sensitivity in Xenopus spinal neurones developing is dissociated cell culture. These cells are initially insensitive, but acquire responses to several agonists over a period of 6 h. 2. Nearly one-third of the neurones were depolarized by γ-aminobutyric acid (GABA) or by both GABA and glycine; these cells were not affected by glutamate. The reversal potential of the ionophoretic GABA response is -35 mV. These neurones are likely to be Rohon-Beard neurones. Roughly two-thirds of the neurones were depolarized by glutamate and hyperpolarized by GABA and by glycine. The reversal potential of the ionophoretic GABA response in -58 mV. These neurones are likely to include motoneurones. 3. A quantitative measure of the sensitivity to a given GABA dose was obtained at early and intermediate stages of development. The mean 'sensitivity index' (ionophoretic sensitivity/input resistance) for both classes of neurones in vitro was initially the same as that seen in Rohon-Beard neurones in vivo. This sensitivity index did not increase with time in culture to attain the value at intermediate stages in vivo. 4. The development of chemosensitivity in Rohon-Beard-like neurones in these cultures resembles that of Rohon-Beard neurones in the spinal cord with respect to the time of onset of response to GABA, the reversal potential, pharmacology and desensitization of these responses, and the spectrum of agonists to which they are sensitive. It differs in the absence of a developmental increase in sensitivity to GABA. The development of chemosensitivity in motoneurone-like neurones in these cultures parallels that of Rohon-Beard-like neurones, with respect to the time of onset and level of sensitivity, as well as susceptibility to pharmacological blockers. 5. Several features of normal neurotransmitter sensitivity, like features of the action potential, differentiate in culture in the absence of normal cellular interactions.
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U2 - 10.1113/jphysiol.1984.sp015328
DO - 10.1113/jphysiol.1984.sp015328
M3 - Article
C2 - 6148408
AN - SCOPUS:0021284520
VL - 353
SP - 143
EP - 155
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 1
ER -