Abstract
We introduce the concept of “silent learning”—the capacity to learn despite neuronal cell-firing being largely absent. This idea emerged from thinking about dendritic computation [1, 2] and examining whether the encoding, expression, and retrieval of hippocampal-dependent memory could be dissociated using the intrahippocampal infusion of pharmacological compounds. We observed that very modest enhancement of GABAergic inhibition with low-dose muscimol blocked both cell-firing and the retrieval of an already-formed memory but left induction of long-term potentiation (LTP) and new spatial memory encoding intact (silent learning). In contrast, blockade of hippocampal NMDA receptors by intrahippocampal D-AP5 impaired both the induction of LTP and encoding but had no effect on memory retrieval. Blockade of AMPA receptors by CNQX impaired excitatory synaptic transmission and cell-firing and both memory encoding and retrieval. Thus, in keeping with the synaptic plasticity and memory hypothesis [3], the hippocampal network can mediate new memory encoding when LTP induction is intact even under conditions in which somatic cell-firing is blocked. It is widely believed that induction of long-term potentiation (LTP) and associated cell-firing is required for new memory formation. Rossato et al. show that memory formation can still occur provided LTP induction is intact even though cell-firing has been prevented using modest GABAergic activation. We refer to this as “silent learning.”
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Current Biology |
| Vol/bind | 28 |
| Nummer | 21 |
| Sider (fra-til) | 3508-3515 |
| Antal sider | 8 |
| ISSN | 0960-9822 |
| DOI | |
| Status | Udgivet - 2018 |