RESUMO
Basal amygdala (BA) neurons guide associative learning via acquisition of responses to stimuli that predict salient appetitive or aversive outcomes. We examined the learning- and state-dependent dynamics of BA neurons and ventral tegmental area (VTA) dopamine (DA) axons that innervate BA (VTADAâBA) using two-photon imaging and photometry in behaving mice. BA neurons did not respond to arbitrary visual stimuli, but acquired responses to stimuli that predicted either rewards or punishments. Most VTADAâBA axons were activated by both rewards and punishments, and they acquired responses to cues predicting these outcomes during learning. Responses to cues predicting food rewards in VTADAâBA axons and BA neurons in hungry mice were strongly attenuated following satiation, while responses to cues predicting unavoidable punishments persisted or increased. Therefore, VTADAâBA axons may provide a reinforcement signal of motivational salience that invigorates adaptive behaviors by promoting learned responses to appetitive or aversive cues in distinct, intermingled sets of BA excitatory neurons.
Assuntos
Tonsila do Cerebelo/fisiologia , Neurônios Dopaminérgicos/fisiologia , Filtro Sensorial/fisiologia , Área Tegmentar Ventral/fisiologia , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Sinais (Psicologia) , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Vias Neurais/fisiologia , Estimulação Luminosa , Punição , Recompensa , Percepção Visual/fisiologiaRESUMO
A vast number of different neuronal activity patterns could each induce a different set of activity-regulated genes. Mapping this coupling between activity pattern and gene induction would allow inference of a neuron's activity-pattern history from its gene expression and improve our understanding of activity-pattern-dependent synaptic plasticity. In genome-scale experiments comparing brief and sustained activity patterns, we reveal that activity-duration history can be inferred from gene expression profiles. Brief activity selectively induces a small subset of the activity-regulated gene program that corresponds to the first of three temporal waves of genes induced by sustained activity. Induction of these first-wave genes is mechanistically distinct from that of the later waves because it requires MAPK/ERK signaling but does not require de novo translation. Thus, the same mechanisms that establish the multi-wave temporal structure of gene induction also enable different gene sets to be induced by different activity durations.