摘要:

AbstractAre different messenger RNA species translated in distinct, limited domains within a cell? For the particular case of the giant R2 neuron fromAplysia californicaan answer to this question is possible for the more abundantly synthesized proteins. After brief labeling with35S‐methionine, the R2 neuron soma was frozen and divided into two or three parts. The newly synthesized proteins were analyzed following two‐dimensional polyacrylamide gel electrophoresis. No evidence for limited domains of synthesis for 26 abundantly synthesized polypeptides in the R2 neuron was fo

ISSN:0022-3034    

DOI:10.1002/neu.480150102

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn RB cells ofAplysia, serotonin, in the presence of TEA, 4AP and Ba, elicits a voltage‐dependent inward current. In Ba‐TEA‐4AP seawater, RB cells showed a negative slope region (NSR) in their current‐voltage (I‐V) relationship when measured at the end of 2‐s commands from a holding potential of −60 mV. Addition of serotonin to the bathing solution enhanced the NSR. When holding potential was lowered to −10 mV, the NSR as well as the effects of serotonin were greatly reduced. Addition of 20 mMcobalt to the bathing solution blocked both the NSR and the inward current produced by serotonin. Changes in potassium concentration produced no consistent shift in voltage sensitivity nor change in amplitude of the current elicited by serotonin. Intracellular injection of cesium sufficient to broaden action potentials did not block the enhancement of NSR by serotonin. These results support the conclusion that in RB cells, serotonin produces a voltage‐dependent current carrie

ISSN:0022-3034    

DOI:10.1002/neu.480150103

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe nervous system of the pond snail,Helisoma trivolvis, was investigated for its ability to synthesize and accumulate3H‐catecholamines from3H‐tyrosine.3H‐Dopamine, but not3H‐norepinephrine, was synthesized by several ganglia. The highest accumulations were found in the cerebral, pedal, and buccal ganglia. The Falck‐Hillarp and glyoxylic acid fluorescence histochemical techniques were applied to the buccal ganglia to visualize dopamine‐containing cells. Fluorescing cells were found on both dorsal and ventral sides of the ganglion. Peripheral nerves of the buccal ganglia also displayed catecholamine fluorescence and accumulated3H‐dopamine. However, no3H‐dopamine synthesis occurred in the cerebral‐buccal connectives, which connect the buccal ganglia with the rest of the central nervous system. Therefore, we conclude that there is a dopaminergic system intrinsic to the buccal ganglia and their p

ISSN:0022-3034    

DOI:10.1002/neu.480150104

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe buccal ganglia of the snail,Helisoma trivolvis, contain an intrinsic system of dopamine‐containing neurons (Trimble, Barker, and Bullard, 1983). Dopamine, when bath applied to the isolated buccal ganglia, activates patterned motor output in a dose‐dependent fashion. Haloperidol blocks the activating effect of dopamine, but the similar activation evoked by serotonin is not blocked by haloperidol. We suggest that there are two separate mechanisms for activating patterned motor output from the buccal ganglia. One is serotonergic, emanating from identified cerebral ganglion cells (Granzow and Kater, 1977), while the other is dopaminergic, involving neurons intrinsic to the buccal gang

ISSN:0022-3034    

DOI:10.1002/neu.480150105

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

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper describes the results of intracellular injections of radiolabelled neurotransmitters and transmitter precursor substances, including glutamate, GABA, aspartate, octopamine, tyramine, tryptophan, and choline, into cell bodies of identified excitatory and inhibitory neurons innervating lobster extensor musculature. The distributions and identities of radioactive substances appearing in axons were examined at various times following injection andin vitroincubation. Injected GABA and glutamate were found in appreciable quantities in both excitatory and inhibitory axons and migrated down axons at an estimated rate of between 16 and 22 mm/day at 12° C, whereas the other substances tested were present in substantially smaller quantities and migrated at an estimated rate of less than 7.5 mm/day at 12° C. Injected GABA,D‐glutamate andL‐glutamate accumulated proximal to ligatures tied around nerves, whereas neither octopamine nor aspartate accumulated proximal to ligatures. Since GABA is the transmitter substance released by inhibitory neurons andL‐glutamate is thought to be released from excitatory nerve terminals, these results are consistent with the suggestion that amino acids serving as neurotransmitters are axonally transported. The specificity of axonal transport does not appear to be restricted to the cognate neurotransmitter, as indicated by the movement of L‐glutamate in inhibitory axons and GABA in excitatory axons and ofD‐glutamate in both excitatory and inhibitory axons, but rather may be relaxed to include substances closely related to the neurotransmitter. Some restrictions, however, are apparently placed on axonal transport of small chaged molecules in these neurons in that other substances tested migrated down nerves at a considerably

ISSN:0022-3034    

DOI:10.1002/neu.480150106

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

年代:1984

数据来源: WILEY

摘要:

AbstractWe present evidence that the pond snailLymnaea stagnalisis capable of aquisition and extensive retention of an appetitively reinforced feeding response after only a single training trial. Food‐deprived snails presented with a single pairing of a phagostimulant (a mixture of sucrose and casein digest) and a novel, non‐food chemostimulus (amyl acetate) subsequently made feeding responses to the amyl acetate and retained the association for at least 19 days. This demonstration of one‐trial, non‐aversive classical conditioning enhances the utility ofLymnaea stagnalisas a model system for the detailed analysis of neural mechanisms underlying pla

ISSN:0022-3034    

DOI:10.1002/neu.480150107

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

年代:1984

数据来源: WILEY

ISSN:0022-3034    

DOI:10.1002/neu.480150108

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

年代:1984

数据来源: WILEY

ISSN:0022-3034    

DOI:10.1002/neu.480150109

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

年代:1984

数据来源: WILEY

ISSN:0022-3034    

DOI:10.1002/neu.480150101

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

年代:1984

数据来源: WILEY