We investigated experience-dependent regulation of neuronal activity in the whisker-to-barrel pathway of the adult mouse using the autoradiographic deoxyglucose (DG) method. Animals were placed in the Lausanne whisker stimulator, and three of their whisker follicles were passively stimulated for a period of 1, 2, or 4 d. After this period, mice received a dose of DG and were placed in a cage containing a pile of wooden sticks. Mice that underwent the same procedure except the passive stimulation served as controls. Patterns of stimulus-dependent DG uptake were studied in the somatosensory cortex and in the trigeminal sensory brainstem complex. DG uptake in the barrels corresponding to the passively stimulated whiskers was lower than in controls. This decrease was present throughout the radial extent of a barrel column and was observed in all passively stimulated animals. Quantitative analysis confirmed these observations and, furthermore, showed a statistically significant decrease in DG uptake in barrels neighboring the passively stimulated ones. In half of the animals, the brainstem nuclei showed a decreased DG uptake in the representation of the passively stimulated whiskers, whereas in the other animals the pattern of DG uptake was as in controls. We propose that the signs of cortical plasticity are due to a mechanism that operates in layer IV and functions as a gate for peripheral sensory activity to enter cortical circuitry.

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✓ A rare case of an epidural intracranial meningioma weighing 1890 gm is reported in a 5-year-old child.

The cereal cyst nematode, Heterodera avenae (Wollenweber, 1924) is one of the most important plant parasitic nematodes of cereals. It is an obligate sedentary endo parasite causing considerable crop losses in wheat, barley and oats worldwide. FMRFamide-like peptides (FLPs) play critical role as neurotransmitters or neuromodulators in the nervous system and proposed as one of the important targets for the plant parasitic nematode management. Therefore, for the first time we have cloned and characterized two neuropeptide genes (flp-12 and flp-16) from the cDNA library of feeding female of H. avenae. Sequence analysis of FLPs revealed that both the neuropeptides are closely related with the parasitic as well as free-living nematodes. The flp-12 contains putative 22 residue long signal peptide at N-terminal suggesting its association with extra-cellular functions, while flp-16 does not contain signal peptide. Besides this, we have found highly conserved motif KFEFIRF in flp-12 and RFGK motif in flp-16. These two flp genes could be interesting and potential targets for functional validation to explore their utility for designing management strategies.

✓ The authors report the successful treatment of two rare cases of primary meningioma of the frontal sinus.

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Administration of leucine at 3 % level in the diet has been shown to increase tryptophan oxygenase activity and to decrease kynureninase activity in the liver and to increase quinolinic acid excretion in the urine of rats fed low amounts of vitamin B₆ (0.5 µg/g diet). Vitamin B₆ at 3 µg/g of diet was able to reverse the effects of leucine on enzyme activities, but not on quinolinic acid excretion. Isoleucine at 0.2 % level could counteract the leucine effect on kynureninase but not on tryptophan oxygenase. Administration of leucine also decreased the 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the brain. Simultaneous administration of isoleucine could counteract the effects of leucine on brain 5-HT and 5-HIAA partially at low amounts of vitamin B₆ but completely at higher levels of vitamin B₆ in the diet.

The arterial pattern of the human body is one of the systems that show a large number of variations. Many reports are available regarding variations of common carotid, external and internal carotid arteries and branches of external carotid artery. We describe a very rare case of lateral position of external carotid artery. The external carotid artery was lateral to the internal carotid artery at the bifurcation of the common carotid artery. The clinical importance of this variation is discussed.