(1) All motoneuron firing during fictive swimming is associated with a tonic depolarization that falls away slowly once firing stops, is increased by hyperpolarizing current, and is reduced by depolarizing current.
(2) Mechanosensory stimulation of an abdominal swimmeret initiates a fictive extension which includes flexion inhibition.
(3) The present experiments indicate that this postlesion activity was due to spinal stretch reflexes because 1) such midsagittal lesions eliminate abdominal muscle nerve activity during fictive vomiting in paralyzed cats in which there are no abdominal stretch reflexes, 2) the abdominal muscles are activated during vomiting by spinal reflexes after upper thoracic cord transections, and 3) the normal 100-ms delay between diaphragmatic and abdominal activation during vomiting is reduced to approximately 20-25 ms after both types of lesions, which is consistent with postlesion abdominal reflex activation.
(4) The turtle spinal cord produces three forms of the fictive scratch reflex in response to tactile stimulation of sites on the body surface.
(5) AA Gill, The Sunday Times's TV critic, said Capaldi's version of the Doctor was "not unlike Richard Dawkins (the scientist), madly science-fictive and theophobic, with selective amnesia and vague formless feelings of charity".
(6) The relative size of each wave of depolarization could vary with different episodes of fictive locomotion in the same unit and among various afferents from the same muscle in the same experiment.
(7) Fictive locomotion appeared spontaneously in decorticate cats (n = 9), with stimulation of the mesencephalic locomotor region (n = 4), and in spinal cats injected with clonidine or nialamide and L-DOPA (n = 4).
(8) The amplitude of Ia inhibitory postsynaptic potentials (IPSPs) varied significantly throughout the fictive step cycle in 14 of the 17 motoneurons tested, and, in 11 of these 14 motoneurons, the Ia IPSPs were maximal during the phase of the step cycle in which the motoneuron was most
(9) To study the effect of this endogenous release of 5-HT on the spinal network generating locomotion, 'fictive locomotion' was induced by bath application of N-methyl-D-aspartate (NMDA, 100 microM).
(10) The possibility that IaIN rhythmicity during fictive locomotion arises from periodic inhibition, possibly from Renshaw cells, was tested by stimulating the reciprocal inhibitory pathway throughout the fictive step cycle.
(11) The results revealed that all cutaneous axons (82 units with resting potential greater than 45 mV) showed fluctuations of their membrane potential (greater than or equal to 0.5 mV) at the rhythm of the fictive locomotion.
(13) In Xenopus embryos there is a constant rostro-caudal delay of 2-5 ms mm-1 during fictive swimming.
(14) The data are consistent with the presence of an excitatory synaptic input alternating with an inhibitory input to the motoneuron during the fictive step cycle.
(15) Fictive vomiting was defined as a series of large bursts of synchronous activity in the phrenic and abdominal (expiratory) nerves (retching) followed by a burst in which the abdominal activity was prolonged (expulsion).
(16) Cutaneous primary afferents were recorded intracellularly during fictive locomotion in decorticated cats with the goal of improving our understanding of how locomotor networks might centrally control the transmission in cutaneous pathways at a presynaptic level.
(17) Another one-third of the VRG E neurons had normal or increased levels of activity when the abdominal nerves were active during fictive vomiting (ABD neurons).
(18) A control of the incoming information from the CB could thus be performed by the central nervous system during fictive locomotion.
(19) During fictive vomiting produced by emetic stimulants in decerebrate, paralyzed cats, only one-third of these neurons had the appropriate firing pattern to contribute to abdominal muscle activity during vomiting.
(20) Unit activities were recorded from cervical neurons during forelimb fictive locomotion.