known about the brain circuits that mediate song acquiMale zebra finches display two song behaviors: disition and production. Referred to collectively as “the rected and undirected singing. The two differ little in song system,” these circuits consist in male zebra the vocalizations produced but greatly in how song is finches of a posterior motor pathway necessary for song delivered. “Directed”...

Huntington disease (HD) is an inherited neurodegenerative disorder characterized by selective death of striatal medium spiny neurons. Intrastriatal injections of glutamate receptor agonists (excitotoxins) recapitulate some neuropathological features of this disorder. Although this model suggests that excitotoxic injury may be involved in HD, the exact mechanisms of cell death in HD and its mode...

Neural progenitor cells persist throughout the adult forebrain subependyma, and neurons generated from them respond to brain-derived neurotrophic factor (BDNF) with enhanced maturation and survival. To induce neurogenesis from endogenous progenitors, we overexpressed BDNF in the adult ventricular zone by transducing the forebrain ependyma to constitutively express BDNF. We constructed a bicistr...

Visualization of neurons is indispensable for the investigation of neuronal circuits in the central nervous system. Virus vectors have been widely used for labeling particular subsets of neurons, and the adeno-associated virus (AAV) vector has gained popularity as a tool for gene transfer. Here, we developed a single AAV vector Tet-Off platform, AAV-SynTetOff, to improve the gene-transduction e...

Manganese overexposure (MnOE) can be neurotoxic. In humans this can occur through occupational exposure, air or water contamination, well water, soy milk, and some baby formulas. In children MnOE has been associated with cognitive and behavioral deficits. The effects of MnOE may be modified by factors such as iron status. We hypothesized that developmental MnOE would be exacerbated by iron defi...

Metabotropic glutamate receptor 4 (mGluR4) is localized mainly to presynaptic membranes in the brain. Rat neostriatum has been reported to contain two types of mGluR4-immunoreactive axon varicosities: small, weakly immunoreactive varicosities that were distributed randomly (type 1) and large, intensely immunoreactive ones that were often aligned linearly (type 2). In the present study, most typ...

Concurrent interval schedules are classic experimental paradigms that are traditionally employed in psychological research on choice behaviour. To analyse the neural basis of choice in a concurrent fixed interval schedule, pigeons were trained to peck on two response keys. Responses were differentially rewarded in key specific short or long time intervals (SI vs. LI). Using tetrodotoxin, we rev...

The avian caudolateral neostriatum (NCL) was first identified on the basis of its dense dopaminergic innervation. This fact and data from lesion studies have led to the notion that NCL might be the avian equivalent of prefrontal cortex (PFC). A key feature of the PFC is the ability to integrate information from all modalities needed for the generation of motor plans. By using antero- and retrog...