Postsynaptic long-term potentiation follows coupling of dendritic glutamate application and synaptic activation

Dendritic depolarization, which seems to be involved in the induction of long-term potentiation (LTP), was elicited by localized glutamate application. When paired to low frequency synaptic activation in the same area, the subsequent changes had features in common with LTP, expressed as an increased probability of firing and shorter spike latency. The EPSP was not significantly increased.     

Responses to the H-2Kba mutant involve recognition of syngeneic Ia molecules

Conventional antigens appear to be recognized by T lymphocytes only when associated with major histocompatibility complex (MHC) antigens. Using antigen-specific proliferation as a model for helper T lymphocytes, it has been demonstrated that Ly1+T cells recognize antigen presented in association with syngeneic Ia molecules. In contrast to responses to conventional antigens, however, a large number of studies have suggested that the stimulation of alloreactive Ly1+T cells, and helper T cells specific for allogeneic cytotoxic T lymphocyte (CTL) responses, involve the direct recognition of Ia alloantigens. For the generation of optimal allogeneic CTL activity it has been proposed that Ly1+T cells recognize allo-Ia antigens directly and provide help to pre-CTLs that respond to allo-H-2K and/or D determinants. Thus, the B6.C.H-2bm1 mutant (bm1, formerly referred to as Hz1), which is believed to consist of a substitution of two amino acids in the H-2Kb antigen, has presented a paradox, for it can stimulate strong mixed lymphocyte culture (MLC), graft versus host and CTL responses by T cells of H-2b haplotype mice in the apparent absence of any alloantigenic differences in the I region. We now present evidence that the stimulation of proliferative and helper T cells by the mutant B6.C.H-2bm1 results from the H-2Kba antigen being recognized in the context of syngeneic Ia determinants. Thus responses to both conventional antigens and allogeneic MHC gene products may proceed via the recognition of antigen in the context of self Ia molecules.     

Volatile constituents of the scent gland reservoir ofAspavia acuminata

Summary Volatile components of the scent gland complex of the adult bug ofAspavia acuminata, an agricultural pest from Nigeria, have been identified by the technique of combined gas chromatograph-mass spectrometry. Of specific interest is the presence in the gland reservoir of hex-2-enal, 4-oxo-hex-2-enal and 4-oxo-oct-2-enal.The author is grateful to the Bayero University Research and Higher Degrees Committee for financial support, Dr B. W. Staddon for his valuable assistance, Dr D. E. Games for arranging mass spectral facilities.     

Development of the new Pacinian corpuscles. Studies on the foreign innervation of mesentery

Zusammenfassung Nach Implantation des proximalen Stumpfes eines afferenten, somatosensiblen Nerven in das Mesenterium einer Katze bilden sich um die auswachsenden Nervenfasern nach 3–5 Monaten neue, aber dem Ort entsprechende Rezeptoren aus, im Fall des Katzenmesenteriums also Pacinische Körperchen, Rezeptoren, die normalerweise nicht im Gebiet des implantierten Nerven vorkommen.     

Effect of praseodymium on drug metabolism in rat liver smooth and rough endoplasmic reticulum

Summary A small i.v. dose (3 mg/kg) of a light lanthanon, praseodymium, impairs the drug metabolizing capacity of both the smooth and rough fractions of rat liver endoplasmic reticulum. This decrease in the activity of drug metabolizing enzymes and in the amount of cytochromes P-450 and b₅ is more pronounced in the rough endoplasmic reticulum fraction.