Glutamate receptor targeting to synaptic populations on Purkinje cells is developmentally regulated

Selective targeting of neurotransmitter receptors to specific synapse populations occurs in adult neurons, but little is known about the development of these receptor distribution patterns. In this study, we demonstrate that a specific developmental switch occurs in the targeting of a receptor to an identified synapse population. Localization of delta and AMPA glutamate receptors at parallel and climbing fiber synapses on the developing Purkinje cells was studied using postembedding immunogold. Delta receptors were found to be abundant on postsynaptic membranes at parallel fiber synapses from postnatal day 10 (P10) to adult. In contrast, delta receptors were found to be high at climbing fiber synapses only at P10 and P14. Thus, a major finding of this paper is that high levels of delta receptors are transiently expressed in climbing fiber synapses in the second postnatal week. Labeling of synapses with anti-delta receptor antibody at P10 was limited to the postsynaptic membrane of excitatory synapses and was absent from GABAergic synapses. Unlike delta receptor immunolabeling, AMPA receptor immunolabeling (GluR2/3 and GluR2 antibodies) was high in the postsynaptic membranes of synapses at early postnatal ages (P2 and P5) and was higher in climbing fiber synapses than in parallel fiber synapses from P10 to adult. The present study shows that synapse-specific targeting of glutamate receptors in Purkinje cells is developmentally regulated, with the postsynaptic receptor composition established during synapse maturation. This composition is not dependent on the nature of the initial establishment of synaptic connections.     

Diagnosis and treatment of congenital thumb hypoplasia

The hypoplastic thumb has a variety of presentations, which have been generalized into a formal classification system that has treatment implications. In most cases, the spectrum of hypoplasia has predictable deficits in terms of tendon and bone absence. The ultimate goal is always the same--to enhance usage of the radial digit. In this article, a straightforward, reliable, and reproducible surgical technique is discussed and illustrated. Pitfalls, indications, and treatment regimes also are discussed to help the physician successfully treat the child with a hypoplastic thumb.     

Nitric oxide synthase inhibitor, aminoguanidine, reduces inflammation and demyelination produced by Theiler''s virus infection

The paper presents current methods of treatment of anxiety disorders: psychotherapeutic and pharmacologic. Therapy of panic disorder differs from therapy of generalised anxiety disorder, the two main categories of anxiety disorders. An anxiety often is present in somatic diseases. Benzodiazepines are the most often used medicines against anxiety.     

Persistent loss of tyrosine hydroxylase immunoreactivity in the substantia nigra after neuroleptic withdrawal

A 37 year woman developed neuroleptic induced parkinsonism that persisted long after the drug had been discontinued. This prompted a study of the effect of an eight week course of haloperidol (HAL) followed by two week withdrawal, on dopaminergic neurons of the substantia nigra in rats. Animals treated with HAL showed a highly significant 32%-46% loss of tyrosine hydroxylase (TH) immunoreactive neurons in the substantia nigra, and 20% contraction of the TH stained dendritic arbour. Neuroleptic drug induced downregulation of nigral dopaminergic neurons may help to explain the persistent parkinsonism found in many patients after withdrawal of medication.     

Vector-borne disease surveillance and natural disasters

Postsurgical changes in the testicle following epididymal surgery may mimic neoplastic transformation on ultrasound evaluation. We report a case in which postoperative ultrasound findings following epididymectomy, which in retrospect were consistent with tubular ectasia of the rete testis, resulted in unnecessary testicular biopsy and orchiectomy.     

The second messenger cAMP elicits eating by an anatomically specific action in the perifornical hypothalamus

We have previously shown that a membrane-permeant analog of cAMP, 8-bromo-cAMP (8-br-cAMP), elicits a vigorous eating response when microinjected into the perifornical hypothalamus (PFH) or lateral hypothalamus (LH) of satiated rats, suggesting that increases in cAMP in these areas may be important in the neural control of eating. To determine the locus of this effect, we compared the ability of 8-br-cAMP (1-100 nmol/0.3 microl) to elicit eating after microinjection into the PFH, LH, or the following bracketing areas: the anterior and posterior LH, paraventricular nucleus of the hypothalamus, thalamus, and amygdala. 8-br-cAMP at 50 nmol elicited eating (>/=3.4 gm in 2 hr) exclusively in the PFH and LH. At 100 nmol, 8-br-cAMP elicited a larger response in these areas and elicited a smaller, more variable response in the thalamus. We similarly mapped the feeding-stimulatory effects of compounds that increase endogenous cellular cAMP in naive rats. Combined microinjection of matched doses (300 nmol) of 3-isobutyl-1-methylxanthine and 7-deacetyl-7-O-(N-methylpiperazino)-gamma-butyryl-forskolin was effective exclusively in the PFH, eliciting an average 2 hr food intake of 8.4 +/- 2.0 gm. Collectively, these results suggest that increases in cellular cAMP within a specific brain site, the PFH, may play a role in the neural stimulation of eating.