High density carbon fiber arrays for chronic electrophysiology, fast scan cyclic voltammetry, and correlative anatomy.

Objective: Multimodal measurements at the neuronal level allow for detailed insight into local circuit function. However, most behavioral studies focus on one or two modalities and are generally limited by the available technology.

Approach: Here, we show a combined approach of electrophysiology recordings, chemical sensing, and histological localization of the electrode tips within tissue.

Cellular-scale silicon probes for high-density, precisely localized neurophysiology.

Neural implants with large numbers of electrodes have become an important tool for examining brain functions. However, these devices typically displace a large intracranial volume compared with the neurons they record. This large size limits the density of implants, provokes tissue reactions that degrade chronic performance, and impedes the ability to accurately visualize recording sites within intact circuits.

Knock-In Rat Lines with Cre Recombinase at the Dopamine D1 and Adenosine 2a Receptor Loci.

Genetically modified mice have become standard tools in neuroscience research. Our understanding of the basal ganglia in particular has been greatly assisted by BAC mutants with selective transgene expression in striatal neurons forming the direct or indirect pathways. However, for more sophisticated behavioral tasks and larger intracranial implants, rat models are preferred.

Publisher Correction: Dissociable dopamine dynamics for learning and motivation.

Change history: In this Article, an extraneous label appeared in Fig. 4b, and has been removed in the online version.

Dissociable dopamine dynamics for learning and motivation.

The dopamine projection from ventral tegmental area (VTA) to nucleus accumbens (NAc) is critical for motivation to work for rewards and reward-driven learning. How dopamine supports both functions is unclear. Dopamine cell spiking can encode prediction errors, which are vital learning signals in computational theories of adaptive behaviour.

Mesolimbic dopamine signals the value of work.

Dopamine cell firing can encode errors in reward prediction, providing a learning signal to guide future behavior. Yet dopamine is also a key modulator of motivation, invigorating current behavior. Existing theories propose that fast (phasic) dopamine fluctuations support learning, whereas much slower (tonic) dopamine changes are involved in motivation.

Basal ganglia beta oscillations accompany cue utilization.

Beta oscillations in cortical-basal ganglia (BG) circuits have been implicated in normal movement suppression and motor impairment in Parkinson's disease. To dissect the functional correlates of these rhythms we compared neural activity during four distinct variants of a cued choice task in rats. Brief beta (∼20 Hz) oscillations occurred simultaneously throughout the cortical-BG network, both spontaneously and at precise moments of task performance.

Selective inhibition of striatal fast-spiking interneurons causes dyskinesias.

Fast-spiking interneurons (FSIs) can exert powerful control over striatal output, and deficits in this cell population have been observed in human patients with Tourette syndrome and rodent models of dystonia. However, a direct experimental test of striatal FSI involvement in motor control has never been performed. We applied a novel pharmacological approach to examine the behavioral consequences of selective FSI suppression in mouse striatum.

Opposite effects of stimulant and antipsychotic drugs on striatal fast-spiking interneurons.

Psychomotor stimulants and typical antipsychotic drugs have powerful but opposite effects on mood and behavior, largely through alterations in striatal dopamine signaling. Exactly how these drug actions lead to behavioral change is not well understood, as previous electrophysiological studies have found highly heterogeneous changes in striatal neuron firing. In this study, we examined whether part of this heterogeneity reflects the mixture of distinct cell types present in the striatum, by distinguishing between medium spiny projection neurons (MSNs) and presumed fast-spiking interneurons (FSIs), in freely moving rats.