Interplay between global and pathway-specific synaptic plasticity in CA1 pyramidal cells

Abstract

Mechanisms underlying information storage have been depicted for global cell-wide and pathway-specific synaptic plasticity. Yet, little is known how these forms of plasticity interact to enhance synaptic competition and network stability. We examined synaptic interactions between apical and basal dendrites of CA1 pyramidal neurons in mouse hippocampal slices. Bursts (50 Hz) of three action potentials (AP-bursts) paired with preceding presynaptic stimulation in stratum radiatum specifically led to LTP of the paired pathway in adult mice (P75). At adolescence (P28), an increase in burst frequency (>50 Hz) was required to gain timing-dependent LTP. Surprisingly, paired radiatum and unpaired oriens pathway potentiated, unless the pre-post delay was shortened from 10 to 5 ms, which selectively potentiated paired radiatum pathway, since unpaired oriens pathway decreased back to baseline. Conversely, the exact same 5 ms pairing in stratum oriens potentiated both pathways, as did AP-bursts alone, which potentiated synaptic efficacy as well as current-evoked postsynaptic spiking. L-type voltage-gated Ca2+ channels were involved in mediating synaptic potentiation in oriens, whereas NMDA and adenosine receptors counteracted unpaired stratum oriens potentiation following pairing in stratum radiatum. This asymmetric plasticity uncovers important insights into alterations of synaptic efficacy and intrinsic neuronal excitability for pathways that convey hippocampal and extra-hippocampal information.

Soluble Aβ Oligomers Impair Dipolar Heterodendritic Plasticity by Activation of mGluR in the Hippocampal CA1 Region

“…However, the induction of plasticity at active synapses can also “spillover” to the neighboring synapses that were inactive during the plasticity induction, thereby producing changes in synaptic strength, referred to as heterosynaptic plasticity ( Chistiakova et al., 2014 ). In addition to same-layer heterosynaptic plasticity, there are reports of neuron-wide heterosynaptic plasticity mediated by basal versus apical dendrites ( Young and Nguyen, 2005 , Hulme et al., 2012 , Berberich et al., 2017 ). We could consider this cell-wide heterosynaptic plasticity as a current dipole change of the homosynaptic plasticity ( Einevoll et al., 2013 ).…”

Sex differences in cholinergic signaling affect functional outcomes for theta–gamma coordination in hippocampal subcircuits following experimental febrile status epilepticus

“…This suggests that the EC–hippocampal circuit and hippocampal throughput are functionally altered by eFSE in male rats. These functional alterations may be the result of altered hippocampal morphology, 6 altered cholinergic modulation of CA1 circuit transition between sensory integration and recall, 44 or altered information‐gating mechanisms 45 . Combined, these changes could make hippocampal function in eFSE males less readily modulated, and therefore less dynamic, in response to increased cognitive demand such as during the active avoidance test.…”