神经元中的记忆

When we learn, we associate a sensory ¹ experience either with other stimuli ³ or with a certain type of behaviour. The neurons in the cerebral ⁴ cortex that transmit the information modify the synaptic connections that they have with the other neurons. According to a generally-accepted model of synaptic plasticity（突触可塑性）, a neuron that communicates with others of the same kind emits an electrical impulse as well as activating ⁵ its synapses ⁶ transiently. This electrical pulse, combined with the signal received from other neurons, acts to stimulate ⁷ the synapses. How is it that some neurons are caught up in the communication interplay even when they are barely connected? This is the crucial chicken-or-egg puzzle of synaptic plasticity that a team led by Anthony Holtmaat, professor in the Department of Basic Neurosciences in the Faculty ⁸ of Medicine at UNIGE, is aiming to solve. The results of their research into memory in silent neurons can be found in the latest edition of Nature. Learning and memory are governed by a mechanism ⁹ of sustainable synaptic strengthening. When we embark ¹⁰ on a learning experience, our brain associates a sensory experience either with other stimuli or with a certain form of behaviour. The neurons in the cerebral cortex responsible for ensuring the transmission of the relevant information, then modify the synaptic connections that they have with other neurons. This is the very arrangement that subsequently enables the brain to optimize ¹¹ the way information is processed when it is met again, as well as predicting its consequences., ,Neuroscientists typically induce electrical pulses in the neurons artificially in order to perform research on synaptic mechanisms ¹²., ,The neuroscientists from UNIGE, however, chose a different approach in their attempt to discover what happens naturally in the neurons when they receive sensory stimuli. They observed the cerebral cortices of mice whose whiskers were repeatedly stimulated ¹³ mechanically without an artificially-induced electrical pulse. The rodents ¹⁴ use their whiskers as a sensor ² for navigating ¹⁵ and interacting; they are, therefore, a key element for perception in mice.