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Long‐term high‐intensity sound stimulation inhibits h current ( I h ) in CA 1 pyramidal neurons
Author(s) -
Cunha Alexandra Olimpio Siqueira,
Ceballos Cesar Celis,
Deus Junia Lara,
Leão Ricardo Maurício
Publication year - 2018
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.13954
Subject(s) - hippocampal formation , stimulation , long term potentiation , chemistry , neuroscience , membrane potential , neurotransmission , biophysics , biology , biochemistry , receptor
Abstract Afferent neurotransmission to hippocampal pyramidal cells can lead to long‐term changes to their intrinsic membrane properties and affect many ion currents. One of the most plastic neuronal currents is the hyperpolarization‐activated cationic current ( I h ), which changes in CA 1 pyramidal cells in response to many types of physiological and pathological processes, including auditory stimulation. Recently, we demonstrated that long‐term potentiation ( LTP ) in rat hippocampal Schaffer‐ CA 1 synapses is depressed by high‐intensity sound stimulation. Here, we investigated whether a long‐term high‐intensity sound stimulation could affect intrinsic membrane properties of rat CA 1 pyramidal neurons. Our results showed that I h is depressed by long‐term high‐intensity sound exposure (1 min of 110 dB sound, applied two times per day for 10 days). This resulted in a decreased resting membrane potential, increased membrane input resistance and time constant, and decreased action potential threshold. In addition, CA 1 pyramidal neurons from sound‐exposed animals fired more action potentials than neurons from control animals; however, this effect was not caused by a decreased I h . On the other hand, a single episode (1 min) of 110 dB sound stimulation which also inhibits hippocampal LTP did not affect I h and firing in pyramidal neurons, suggesting that effects on I h are long‐term responses to high‐intensity sound exposure. Our results show that prolonged exposure to high‐intensity sound affects intrinsic membrane properties of hippocampal pyramidal neurons, mainly by decreasing the amplitude of I h .