摘要:

AbstractThe objective of this work is to describe the glomerular organization of the deutocerebrum inBlaberus craniiferand to test the hypothesis that the glomeruli are identifiable. The problem is studied using the techniques of analytical geometry, i.e., by measuring the location of the glomeruli in cartesian coordinate systems. Computerized geometrical and statistical techniques are described for the three‐dimensional reconstruction and quantitative study of these brain structures. The invariance of the glomerular organization, and consequently the identifiability of the glomeruli, is based on three criteria: (1) the number of glomeruli per hemideutocerebrum (hDTC) is a constant (109); (2) the position of the glomeruli is symmetrical in the two sides of one individual and identical in the same side of two individuals, except for small local variations, (3) the dimensions of two positionally homologous glomeruli are statistically equal in the same and in different individuals, except for a macroglomerulus which is found only in the male. The causes of variability, from experimental and biological origin, are discussed and quantitatively evaluated. The interindividual biological variability, not ascribable to differences in size between brains, expressed as a 95% interval, is estimated to be 27 μm for the location of glomeruli and 12 μm for the diameter of glomer

ISSN:0022-3034    

DOI:10.1002/neu.480110202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThere are nine “giant vertical” neurons in the lobula plate of the fly optic lobe. Intracellular recordings were obtained from the three most peripheral of these cells. These cells respond to a light flash with graded changes in the membrane potential. The response consists of an “on” transient, a sustained depolarization, an increase in membrane potential fluctuations, and an “off” transient. Signal averaging showed that only the “on” and “off” transients are correlated to the stimulus. A pattern of horizontally oriented stripes moving in the vertical direction evokes a response larger than the response to a stationary pattern. The response is most sensitive to vertical movement; motion in the downward direction evokes a net membrane potential depolarization, and upward motion results in a net hyperpolarization. We conclude that the giant vertical cells function primarily as vertical motion detectors and that the direction of the motion is encoded in the polarity of the shift in the

ISSN:0022-3034    

DOI:10.1002/neu.480110203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe cilio‐excitatory serotonergic innervation of lateral gill cilia ofMytilus eduliswas studiedin vivo. Peripheral serotonin release was dependent on the external calcium concentration. Serotonin release was inhibited by autodialyzing calcium from the tissue or by increasing the calcium concentration in the medium, as determined by measuring ciliary activity stroboscopically and by biochemical and radioassays of serotonin. Lithium also inhibited serotonin release when added to the external bathing medium. Concomitantly, altering calcium concentrations altered the degree of inhibition of serotonin release caused by lithium. The study demonstrates that the terminal release of the monoamine serotonin is a calcium‐dependent mechanism. The pharmacological effects of lithium in this system appear to be interrelated with the calcium‐dependent releasing mech

ISSN:0022-3034    

DOI:10.1002/neu.480110204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe frequency characteristics of tetanic and post‐tetanic potentiation of the septohippocampal and hippocampal commissural systems were studied in the acute rabbit preparation. Glass micropipettes were employed to stimulate the medial septal (MSR) and contralateral CA1 (cCA1) regions. Extracellular postsynaptic potentials were recorded in the stratum radiatum and stratum oriens layers of dorsal CA1. Low frequencies of stimulation (2–12 Hz) and brief stimulus trains (7 or 16 stimuli) ensured that only short‐term effects appeared in the data. With MSR and cCA1 stimulation, tetanic potentiation became pronounced at 4 Hz, and plateaued at 6–8 Hz. Thus potentiation was found to be pronounced within the range of the rabbit hippocampal theta rhythm. No differences were found in the characteristics of potentiation evoked by stimulation of MSR and cCA1. Post‐tetanic potentiation lasting 6–12 sec was found. Again, potentiation characteristics did not depend on stimulus site, suggesting a common mechanism for the pathways studied. A two‐factor mechanism was proposed to account for the post‐tetanic po

ISSN:0022-3034    

DOI:10.1002/neu.480110205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractExposing intact nerves ofAplysiato exogenous CoCl2was sufficient to fill neurons by axonal iontophoresis. There were no significant differences between filling intact nerves and nerves whose ends had been cut. Nonneuronal elements were not filled appreciably. These results show that Co2+can cross intact axonal membranes and suggest that in tracing neuronal pathways Co2+may not remain confined to neurons whose interiors are directly exposed to it.

ISSN:0022-3034    

DOI:10.1002/neu.480110206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractHomogenates of cricket (Acheta domesticus) central nervous system (CNS) specifically bind the potent muscarinic ligand [3H]‐QNB. Binding assay and pharmacologic data indicate that the cricket CNS contains a high density of muscarinic cholinergic binding sites. These sites appear to be a unique class of invertebrate cholinergic receptor with properties distinct from those of previously described nicotinic receptor

ISSN:0022-3034    

DOI:10.1002/neu.480110207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA method for obtaining intracellular recordings from central neurons of insects during the performance of ecdysial behaviors is described. Body wall turgor must be restored to high levels in order to provide the CNS with appropriate sensory feedback required for the generation of motor output. This is accomplished by installing the insect in a decompression chamber so that an opening in the animal's ventral surface communicates with the atmosphere. Reduction of chamber pressure causes expansion of the insect's body, and access to thoracic ganglia is provided by the ventral opening in the animal's body wall. It is suggested that adaptations of this technique to invertebrates with hydrostatic skeletons is possible and would permit electrophysiological studies of behaviors which normally require high blood pressures for their performance.

ISSN:0022-3034    

DOI:10.1002/neu.480110208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0022-3034    

DOI:10.1002/neu.480110201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY