REDUCED CAPABILITIES OF SYNAPTIC TRANSMISSION IN AGED RATS

被引:56
作者
SMITH, DO
机构
[1] Department of Physiology, University of Wisconsin Medical School, Madison
基金
美国国家卫生研究院;
关键词
D O I
10.1016/0014-4886(79)90210-3
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Synaptic transmission at the neuromuscular junction of the rat phrenic nerve-diaphragm muscle was studied in aged and young, control rats; their ages were 24 to 26 and 12 to 13 months, respectively. The resting potential of the diaphragm muscle cells was found to be consistently lower in the old animals than in the controls. Membrane input resistance and capacitance were not significantly different. The rate of occurrence of miniature end-plate potentials (MEPPs) in old rats was 1.75 times higher than in the controls; the distribution of intervals between the times of occurrence of successive MEPPs was exponential in both cases, however. In Mg2+-blocked preparations, facilitation and posttetanic potentiation were observed; differences between data obtained from both age groups were not significant. In curare-blocked preparations, synaptic depression occurred during repetitive nerve stimulation. The depression was more severe in the aged animals; this difference was consistent and independent of the rate of stimulation. Repetitive nerve stimulation led to action potential conduction block in the presynaptic terminals of both age groups; however, failure occurred at lower frequencies and shorter times of stimulation in the aged animals. The block appeared to be associated with membrane depolarization. We conclude that the capability to sustain transmission is diminished at the neuromuscular junction of aged rats; this could underlie the deterioration of synaptic structures observed during senescence. © 1979.
引用
收藏
页码:650 / 666
页数:17
相关论文
共 38 条
[1]   EFFECTS OF VINBLASTINE AND COLCHICINE ON NEURAL REGULATION OF MUSCLE [J].
ALBUQUERQUE, EX ;
WARNICK, JE ;
SANSONE, FM ;
ONUR, R .
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES, 1974, 228 (MAR22) :224-243
[2]   AGE CHANGES IN CONDUCTION VELOCITY, REFRACTORY PERIOD, NUMBER OF FIBERS, CONNECTIVE TISSUE SPACE AND BLOOD VESSELS IN SCIATIC NERVE OF RATS [J].
BIRREN, JE ;
WALL, PD .
JOURNAL OF COMPARATIVE NEUROLOGY, 1956, 104 (01) :1-16
[3]   PHYSIOLOGICAL CHANGES IN AGING MUSCLES [J].
CAMPBELL, MJ ;
MCCOMAS, AJ ;
PETITO, F .
JOURNAL OF NEUROLOGY NEUROSURGERY AND PSYCHIATRY, 1973, 36 (02) :174-182
[4]   PATHOLOGICAL-CHANGES DURING AGING IN BARRIER-REARED FISCHER 344 MALE RATS [J].
COLEMAN, GL ;
BARTHOLD, SW ;
OSBALDISTON, GW ;
FOSTER, SJ ;
JONAS, AM .
JOURNALS OF GERONTOLOGY, 1977, 32 (03) :258-278
[5]  
Couteaux R, 1960, STRUCTURE FUNCTION M, P337
[6]  
DIXON WJ, 1957, INTRO STATISTICAL AN, P123
[7]  
FATT P, 1952, J PHYSIOL-LONDON, V117, P109
[8]  
FELDMAN ML, 1976, NEUROBIOL AGING, P211
[9]   AGING OF NEUROMUSCULAR APPARATUS [J].
FROLKIS, VV ;
MARTYNENKO, OA ;
ZAMOSTYAN, VP .
GERONTOLOGY, 1976, 22 (04) :244-279
[10]   DIMINISHED AXONAL-TRANSPORT OF GLYCOPROTEINS IN SENESCENT RAT-BRAIN [J].
GEINISMAN, Y ;
BONDAREFF, W ;
TELSER, A .
MECHANISMS OF AGEING AND DEVELOPMENT, 1977, 6 (05) :363-378