Behavioral manipulations such as housing in an enriched environment have been shown to increase brain weight and visual cortical thickness. The present study was designed to test whether skill learning or repetitive movements can alter the thickness of the motor cortex. One group of 6-mo-old Long-Evans female rats learned motor skills on an obstacle course that increased in difficulty over training and required balance and coordination. A second group ran voluntarily in exercise wheels attached to their home cage but had little opportunity for skill learning. The third group was handled daily but received no opportunity for learning or exercise. Each condition lasted 26-29 d. The skill-learning and exercise conditions had greater heart weight, and the exercise condition had greater adrenal gland weights than controls. The thickness of the motor cortex was measured in four coronal planes between −2.33 mm to −0.3 mm from bregma. Regions of interest that corresponded to published maps of forelimb and hind-limb representations were analyzed together. Rats in the skill-learning condition had significantly thicker medial cortical areas in the two anterior planes (−0.8 and −0.3 mm from bregma). These regions correspond to previously mapped hind-limb representations. The exercise group had greater thickness of the medial region at −0.8 mm from bregma. Cortical thickness in all conditions varied significantly along the medial to lateral axis. For both treatments, the effects were restricted to medial and anterior regions of interest rather than posterior or lateral regions of interest. The results indicate that robust exercise, in addition to skill learning, is capable of altering the thickness of the motor cortex, but that the effects are restricted rather than distributed within the regions studied.

A 30-cytokine protein microarray was used to screen for cytokine profile changes in HIV-infected patients in response to highly active antiretroviral therapy (HAART). Serum cytokines showing significant changes were confirmed by enzyme immunoassay. Monokine induced by gamma-interferon (MIG) and interferon-inducible protein-10 (IP-10) levels significantly decreased after 24 weeks of HAART. Protein microarrays are useful for initial screening of novel cytokine expression. Further studies are needed to elucidate the role of MIG and IP-10 in response to HAART.

No abstract

An HIV-negative man with pharyngeal gonorrhea had a positive test-of-cure (nucleic acid amplification test) result 7 days after treatment with ceftriaxone/azithromycin. Neisseria gonorrhoeae Multi-Antigen Sequencing Type 1407 and mosaic pen A (XXXIV) gene were identified in the test-of-cure specimen, and culture was negative. Retreatment with ceftriaxone 500 mg intramuscularly plus azithromycin 2 g orally yielded a negative test-of-cure result.

This experiment addressed (1) the importance of conjunctive stimulus presentation for morphological plasticity of cerebellar Purkinje cells and inhibitory interneurons and (2) whether plasticity is restricted to the spiny branches of Purkinje cells, which receive parallel fiber input. These issues were investigated in naive rabbits and in rabbits that received paired or unpaired presentations of the conditioned stimulus (CS) and unconditioned stimulus (US). To direct CS input to the cerebellar cortex, pontine stimulation served as the CS. Air puffs to the cornea served as the US. Paired condition rabbits received pontine stimulation for 350 msec paired with a coterminating 100-msec air puff. Unpaired condition rabbits received the same stimuli in a pseudorandom order at 1- to 32-sec intervals. Rabbits were trained for a mean of 12 days. Naive rabbits received no treatment. In Golgi-stained Purkinje neurons in lobule HVI, total dendritic length, main branch length, total spiny branch length, and number of spiny branch arbors were all greater in the naive group than in the paired and unpaired groups, which did not differ. No differences were found between the hemispheres ipsilateral and contralateral to the trained eye. The dendritic length and number of branches for inhibitory interneurons did not differ across groups. The Purkinje cell morphological changes detected with these methods do not appear to be uniquely related to the conjunctive activation of the CS and US in the paired condition.