title: Age-dependent actions of dopamine on inhibitory synaptic transmission in superficial layers of mouse prefrontal cortex.
abstract: Numerous developmental changes in the nervous system occur during the first several weeks of the rodent lifespan. Therefore, many characteristics of neuronal function described at the cellular level from in vitro slice experiments conducted during this early time period may not generalize to adult ages. We investigated the effect of dopamine (DA) on inhibitory synaptic transmission in superficial layers of the medial prefrontal cortex (PFC) in prepubertal [postnatal age (P; days) 12-20], periadolescent (P30-48), and adult (P70-100) mice. The PFC is associated with higher-level cognitive functions, such as working memory, and is associated with initiation, planning, and execution of actions, as well as motivation and cognition. It is innervated by DA-releasing fibers that arise from the ventral tegmental area. In slices from prepubertal mice, DA produced a biphasic modulation of inhibitory postsynaptic currents (IPSCs) recorded in layer II/III pyramidal neurons. Activation of D2-like receptors leads to an early suppression of the evoked IPSC, which was followed by a longer-lasting facilitation of the IPSC mediated by D1-like DA receptors. In periadolescent mice, the D2 receptor-mediated early suppression was significantly smaller compared with the prepubertal animals and absent in adult animals. Furthermore, we found significant differences in the DA-mediated lasting enhancement of the inhibitory response among the developmental groups. Our findings suggest that behavioral paradigms that elicit dopaminergic release in the PFC differentially modulate inhibition of excitatory pyramidal neuron output in prepuberty compared with periadolescence and adulthood in the superficial layers (II/III) of the cortex.
authors.affiliation: Department of Molecular and Integrative Physiology, Department of Pharmacology, Beckman Institute for Advanced Scienceand Technology, University of Illinois, Urbana, IL, USA. kushpaul@illinois.edu
authors.forename: Kush
authors.initials: K
authors.lastname: Paul
authors.forename: Charles L
authors.initials: CL
authors.lastname: Cox
mesh_terms: D000367:Age Factors; D000818:Animals; D003071:Cognition / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects*; D008570:Memory, Short-Term / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D055369:Miniature Postsynaptic Potentials / Q000187:drug effects*; D009042:Motivation / Q000187:drug effects; D017397:Prefrontal Cortex / Q000166:cytology / Q000502:physiology*; D017966:Pyramidal Cells / Q000378:metabolism / Q000502:physiology; D017447:Receptors, Dopamine D1 / Q000819:agonists; D017448:Receptors, Dopamine D2 / Q000819:agonists
chemical_list: D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D004298:Dopamine