Optogenetic fMRI and electrophysiological identification of region-specific connectivity between the cerebellar cortex and forebrain.

Complex animal behavior is produced by dynamic interactions between discrete regions of the brain. As such, defining functional connections between brain regions is critical in gaining a full understanding of how the brain generates behavior. Evidence suggests that discrete regions of the cerebellar cortex functionally project to the forebrain, mediating long-range communication potentially important in motor and non-motor behaviors. However, the connectivity map remains largely incomplete owing to the challenge of driving both reliable and selective output from the cerebellar cortex, as well as the need for methods to detect region specific activation across the entire forebrain. Here we utilize a paired optogenetic and fMRI (ofMRI) approach to elucidate the downstream forebrain regions modulated by activating a region of the cerebellum that induces stereotypical, ipsilateral forelimb movements. We demonstrate with ofMRI, that activating this forelimb motor region of the cerebellar cortex results in functional activation of a variety of forebrain and midbrain areas of the brain, including the hippocampus and primary motor, retrosplenial and anterior cingulate cortices. We further validate these findings using optogenetic stimulation paired with multi-electrode array recordings and post-hoc staining for molecular markers of activated neurons (i.e. c-Fos). Together, these findings demonstrate that a single discrete region of the cerebellar cortex is capable of influencing motor output and the activity of a number of downstream forebrain as well as midbrain regions thought to be involved in different aspects of behavior.

Aspiration and triamcinolone acetonide injection of wrist synovial cysts in children.

PURPOSE: The aim of this case series report is to assess the effectiveness of aspiration and injection of triamcinolone acetonide for treatment of wrist synovial cysts in children. METHODS: Twenty-one records of pediatric patients with synovial cyst on the wrist treated with aspiration and triamcinolone acetonide injection were selected for analysis of their outcomes. All cases were aspirated and injected at the operating room under mask induction anesthesia. Three categories were used to classify the patients' outcomes: (1) successful treatment with no recurrence, (2) successful treatment with residual sclerotic lump, and (3) recurrence of cyst. RESULTS: Fourteen females and 7 males with an average age of 7.2 years had a mean time with the cyst of 1 year. All children were asymptomatic. After aspiration, 13 (62%) of 21 patients experienced successful treatment of the synovial cyst with no recurrence after a single intervention. Five patients had a residual lump at the site of the cyst (24%), which disappeared after an average of 6 months. Three patients experienced true recurrence of the synovial cyst (14%). Average follow-up was 2.5 years. CONCLUSIONS: Aspiration and injection of triamcinolone accounted for a considerable reduction in recurrence. Aspiration and triamcinolone acetonide injection of wrist synovial cysts is an effective and safe treatment that may be considered as first-line treatment in the pediatric population if there is no resolution after 1 year of observation.