PMID- 4093877
OWN - NLM
STAT- MEDLINE
DCOM- 19860328
LR  - 20190511
IS  - 0022-3751 (Print)
IS  - 1469-7793 (Electronic)
IS  - 0022-3751 (Linking)
VI  - 369
DP  - 1985 Dec
TI  - Development of the monosynaptic stretch reflex in the rat: an in vitro study.
PG  - 127-44
AB  - The properties and development of the stretch reflex pathway were investigated in 
      new-born and fetal rats using the isolated spinal cord-hind limb preparation. 
      Muscle afferent discharge was elicited by small stretch of the triceps surae 
      muscle in the new-born rat and in the fetus. It appeared as early as embryonic 
      day 18.5. Ramp-and-hold stretch elicited only phasic discharges in most afferent 
      fibres. A phasic reflex response was evoked in the triceps surae muscle by brief 
      or ramp-and-hold stretch of the muscle in the new-born rat. The threshold stretch 
      required for evoking the reflex response was close to that for eliciting the 
      afferent discharge. A reflex response in the triceps surae muscle was also evoked 
      by electrical stimulation of the triceps surae muscle nerve or the sciatic nerve 
      in the new-born rat. Excitatory post-synaptic potentials (e.p.s.p.s) in the 
      triceps surae motoneurones were evoked by stimulation of the muscle nerve in the 
      new-born rat. The amplitude of the e.p.s.p.s was large enough to generate spike 
      potentials. Homonymous e.p.s.p.s were significantly larger than heteronymous 
      e.p.s.p.s. The amplitudes of the e.p.s.p.s were very susceptible to the rate of 
      stimulus repetition. At a stimulus frequency of 10 Hz they were depressed to less 
      than 10% of the control value. Presynaptic impulses evoked by stimulation of 
      afferents in the muscle nerve appear in the motor nucleus less than 1.0 ms before 
      the onset of synaptically evoked field potentials. The interval between the 
      arrival of impulses evoked by dorsal root stimulation and the onset of e.p.s.p.s 
      in motoneurones was 0.56 +/- 0.16 ms, indicating monosynaptic transmission from 
      the primary afferents to the motoneurones. In the fetus, a reflex response in the 
      triceps surae muscle was observed following a small stretch of the muscle (or 
      electrical stimulation of the sciatic nerve) in all preparations at embryonic day 
      20.5 and in about half of those examined at embryonic day 19.5. Neither 
      stimulation evoked a reflex response at embryonic day 18.5. Latencies of the 
      reflex responses evoked by muscle stretch or by nerve stimulation were similar to 
      those in the new-born rat. It is concluded that the monosynaptically evoked 
      stretch reflex response in the triceps surae muscle first appear at embryonic day 
      19.5. Natural and electrical stimulation of the plantar skin evoked a reflex 
      response with long latencies in flexor muscles. Such a cutaneous reflex was first 
      present at embryonic day 17.5, two days earlier than the onset of the stretch 
      reflex.
FAU - Kudo, N
AU  - Kudo N
FAU - Yamada, T
AU  - Yamada T
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - J Physiol
JT  - The Journal of physiology
JID - 0266262
SB  - IM
MH  - Action Potentials
MH  - Afferent Pathways/growth & development
MH  - Animals
MH  - Hindlimb
MH  - In Vitro Techniques
MH  - Motor Neurons/physiology
MH  - Muscles/embryology/*physiology
MH  - Neurons, Afferent/physiology
MH  - Rats
MH  - *Reflex, Stretch
MH  - Sensory Thresholds/physiology
MH  - Skin/innervation
MH  - Spinal Cord/*physiology
PMC - PMC1192640
EDAT- 1985/12/01 00:00
MHDA- 1985/12/01 00:01
PMCR- 1985/12/01
CRDT- 1985/12/01 00:00
PHST- 1985/12/01 00:00 [pubmed]
PHST- 1985/12/01 00:01 [medline]
PHST- 1985/12/01 00:00 [entrez]
PHST- 1985/12/01 00:00 [pmc-release]
AID - 10.1113/jphysiol.1985.sp015892 [doi]
PST - ppublish
SO  - J Physiol. 1985 Dec;369:127-44. doi: 10.1113/jphysiol.1985.sp015892.