Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, 117485, Russia.
Department of Psychological Sciences, University of Connecticut, Storrs CT, 06269, USA.
Biochem Biophys Res Commun. 2024 Nov 12;733:150736. doi: 10.1016/j.bbrc.2024.150736. Epub 2024 Sep 21.
Long-term changes of synaptic transmission can be induced by Hebbian-type homosynaptic mechanisms which require activation of both pre- and postsynapse and mediate associative learning, as well as by heterosynaptic mechanisms which do not require activation of the presynapse and are non-associative. The rules for induction of homosynaptic plasticity depend on the distance of the synapse from the soma. Does induction of heterosynaptic plasticity also depend on synaptic location? Here, we investigated heterosynaptic changes in pharmacologically isolated glutamatergic inputs arriving at either the proximal or the distal segments of the apical dendrite of layer 2/3 pyramidal neurons in rat visual cortex. We show that bursts of action potentials evoked without presynaptic stimulation induced potentiation of proximal inputs while having little effect on distal inputs. Such gradient of plasticity could be related to the attenuation of backpropagating action potentials along the dendrites. Thus, the location of the synapse on the dendritic tree is a determinant not only for homosynaptic but also for heterosynaptic plasticity.
长期的突触传递变化可以通过海伯型同突触机制诱导，该机制需要前突触和后突触的激活，介导联想学习，也可以通过非联想的异突触机制诱导，该机制不需要前突触的激活。同突触可塑性诱导的规则取决于突触与胞体的距离。异突触可塑性的诱导是否也取决于突触位置？在这里，我们研究了在药理学上分离的谷氨酸能输入到达大鼠视觉皮层 2/3 层锥体神经元的近端或远端树突段时的异突触变化。我们发现，在没有前突触刺激的情况下诱发的动作电位爆发诱导了近端输入的增强，而对远端输入几乎没有影响。这种可塑性的梯度可能与沿树突传播的逆行动作电位的衰减有关。因此，突触在树突上的位置不仅是同突触可塑性的决定因素，也是异突触可塑性的决定因素。
