PMID- 1704834
OWN - NLM
STAT- MEDLINE
DCOM- 19910328
LR  - 20220309
IS  - 0013-4694 (Print)
IS  - 0013-4694 (Linking)
VI  - 78
IP  - 2
DP  - 1991 Feb
TI  - Recovery functions of fast frequency potentials in the initial negative wave of 
      median SEP.
PG  - 116-23
AB  - Following far-field potential of P14 after median nerve stimulation, we 
      identified several small wavelets, designated here as fast frequency potentials 
      or FFP, over the ascending and descending phases of the major negative wave of 
      'N20.' In 10 normal subjects who had well defined FFP, namely N16, N17, N18 and 
      N19, we studied recovery functions of FFP by applying paired (condition and test) 
      stimuli of various interstimulus intervals (ISIs) ranging from 3 to 150 msec. 
      Recovery of FFP was determined by the difference wave forms, i.e., subtracting 
      the response of conditioning stimuli from the response to paired stimuli. 
      Measuring latencies and amplitude of FFP and also of the far-field potential of 
      P14, we found recoveries of P14 and each FFP to be different; P14 recovered with 
      the shortest ISI while progressively longer ISIs were required for full recovery 
      of the later FFP. This finding suggests the existence of progressively increased 
      number of interspersed synapses from the early to late FFP. It is unlikely that 
      FFP represents passage of the afferent volley from one anatomical site to the 
      next, but rather that they are cortically generated via a closely situated 
      polysynaptic network. The polysynaptic nature of FFP is consistent with the 
      observation that they disappear in sleep and also during anesthesia. The study 
      indicates that FFPs represent different physioanatomical systems from the primary 
      negative wave of 'N20' that results from specific sensory input to the primary 
      sensory cortex.
FAU - Emori, T
AU  - Emori T
AD  - Department of Neurology, University of Iowa, College of Medicine, Iowa City 
      52242.
FAU - Yamada, T
AU  - Yamada T
FAU - Seki, Y
AU  - Seki Y
FAU - Yasuhara, A
AU  - Yasuhara A
FAU - Ando, K
AU  - Ando K
FAU - Honda, Y
AU  - Honda Y
FAU - Leis, A A
AU  - Leis AA
FAU - Vachatimanont, P
AU  - Vachatimanont P
LA  - eng
PT  - Journal Article
PL  - Ireland
TA  - Electroencephalogr Clin Neurophysiol
JT  - Electroencephalography and clinical neurophysiology
JID - 0375035
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Electric Stimulation
MH  - Electroencephalography
MH  - *Evoked Potentials, Somatosensory
MH  - Female
MH  - Humans
MH  - Male
MH  - Median Nerve/*physiology
MH  - Middle Aged
EDAT- 1991/02/01 00:00
MHDA- 1991/02/01 00:01
CRDT- 1991/02/01 00:00
PHST- 1991/02/01 00:00 [pubmed]
PHST- 1991/02/01 00:01 [medline]
PHST- 1991/02/01 00:00 [entrez]
AID - 0013-4694(91)90111-G [pii]
AID - 10.1016/0013-4694(91)90111-g [doi]
PST - ppublish
SO  - Electroencephalogr Clin Neurophysiol. 1991 Feb;78(2):116-23. doi: 
      10.1016/0013-4694(91)90111-g.