Comparison of the Ionic Currents Modulated during Activity-Dependent and Normal Presynaptic Facilitation

Autor/inn/en	Hawkins, Robert D.; Kandel, Eric R.
Titel	Comparison of the Ionic Currents Modulated during Activity-Dependent and Normal Presynaptic Facilitation
Quelle	In: Learning & Memory, 26 (2019) 12, S.449-454 (6 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1072-0502
Schlagwörter	Associative Learning; Classical Conditioning; Brain; Animals; Differences + Suchen Sie Ihr Suchwort? Gehirn; Animal; Tier; Tiere; Unterscheiden
Abstract	One of the major questions in psychology is whether associative and nonassociative learning are fundamentally different or whether they involve similar processes and mechanisms. We have addressed this question by comparing mechanisms of a nonassociative form of learning, sensitization, and an associative form of learning, classical conditioning of the siphon-withdrawal reflex of hermaphroditic Aplysia. In an analog of differential conditioning, action potentials in one siphon sensory neuron (SN) were paired with shock to the pedal nerves, producing activity-dependent presynaptic facilitation, and action potentials in another SN were unpaired with the shock as a control. The difference between paired and unpaired training is a measure of associative plasticity. Before and after this training, we voltage clamped each SN and measured the outward current during depolarizing pulses. There was a significantly greater decrease in the net outward current in the paired SN than in the unpaired SN. We obtained similar results when we substituted the depolarizing voltage clamp pulse for action potentials during training. We then bathed the ganglion in serotonin as a measure of nonassociative plasticity. The current that was modulated differentially (paired-unpaired) had time and voltage dependencies similar to the current that was modulated by serotonin (Is). These results suggest that an associative form of plasticity, activity-dependent presynaptic facilitation underlying conditioning, involves enhanced modulation of the same ionic current as a nonassociative form, normal presynaptic facilitation underlying sensitization. (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01