Dendrites are more spiny on mature hippocampal neurons when synapses are inactivated.
Dendrites of CA1 pyramidal neurons in mature rat hippocampal slices were exposed to different levels of synaptic activation. In some slices, synaptic transmission was blocked with glutamate receptor antagonists, sodium and calcium channel blockers and/or a nominally calcium-free medium with high magnesium. In other slices, synapses were activated with low-frequency control stimulation or repeated tetanic stimulation. In slices with blocked synaptic transmission, dendrites were spinier than in either of the activated states. Thus, mature neurons can increase their numbers of spines, possibly compensating for lost synaptic activity.
Kirov
S A
SA
Division of Neuroscience in the Department of Neurology, Children's Hospital and Harvard Medical School, Enders 260, 300 Longwood Ave., Boston, Massachusetts 02115, USA.
Harris
K M
KM
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D003712:Dendrites / Q000187:drug effects*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000648:ultrastructure; D051381:Rats; D020318:Rats, Long-Evans; D026941:Sodium Channel Blockers; D009435:Synaptic Transmission / Q000187:drug effects*
D002121:Calcium Channel Blockers; D018691:Excitatory Amino Acid Antagonists; D026941:Sodium Channel Blockers