Benjamin E Johnson

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It is widely believed that long-term depression (LTD) and its counterpart, long-term potentiation (LTP), involve mechanisms that are crucial for learning and memory. However, LTD is difficult to induce in adult cortex for reasons that are not known. Here we show that LTD can be readily induced in adult cortex by the activation of NMDA receptors (NMDARs),(More)
BACKGROUND AND OBJECTIVES Sarcopenia, which is subclinical loss of skeletal muscle mass, is commonly observed in patients with malignancy. The objective of this study is to determine the correlation between sarcopenia and operative complications following pancreatectomy for cancer. METHODS A retrospective review of a pancreatectomy database was performed.(More)
The effect of thyroxine (T4) and/or recombinant chicken growth hormone (rcGH) supplementation on immune function and on immune cell maturation was examined in Obese strain chickens. Day-old Obese strain chicks received the control treatments or were treated with either T4 (supplemented in the diet), T4-rcGH, or rcGH (by daily injection) in a full factorial(More)
The effect of hypophysectomy and recombinant growth hormone (rcGH) treatment on the growth and development of the immune system was investigated in young chickens. Flow cytometric analysis of cell surface markers revealed no changes in the proportion of thymocytes expressing CT-1a, CD4, and/or CD8 among any of the treatment groups. In contrast, the(More)
During development neuronal circuitries are refined by activity. Here we studied the role of spontaneous electrical activity in the regulation of synapse formation in the intact newborn (Postnatal Day 3; P3) rat hippocampus in vitro. The blockade of the spontaneous network activity with TTX led to an increase in the number of functional excitatory synapses(More)
The yield of thymine-containing dimers produced in mouse skin DNA in vivo by 290 nm ultraviolet radiation was shown to increase with dose up to around 2000 J/m2 and subsequently at a much slower rate up to 8000 J/m2. The study of wavelength dependence of dimer formation in skin indicated that 290 nm was the most effective wavelength of those investigated,(More)
The relative influence of Ah vs H-2 genotype on the outcome of Trichinella spiralis (Tsp) infections of mice was examined following methylcholanthrene (MC) treatment. Female mice of four inbred strains were treated with MC and infected 24 h later with Tsp muscle larvae. The strains, with their respective major histocompatibility complex (MHC) haplotype,(More)
Hypothyroid K-strain chickens were produced by neonatal thyroidectomy and treatment with 6-propyl-2-thiouracil. Thyroidectomized birds were given 0, 1.5, 4.5, 15, or 45 micrograms/kg body wt of triiodothyronine (T3) by daily injection. At 5 weeks of age, thymocytes were prepared for flow cytometric analysis of CT-1a, CD3, CD4, and CD8 expression.(More)