title: Enhancement of electrically elicited startle by amygdaloid stimulation.
abstract: Previous experiments showed that acoustic startle amplitude can be enhanced by electrical stimulation of the amygdala. Because the acoustic startle pathway is organized in a serial fashion, startle can be elicited electrically with progressively shorter latencies by stimulating different points along this pathway [i.e., ventral cochlear nucleus (VCN), paralemniscal zone (PLZ), nucleus reticularis pontis caudalis (RPC) or medial longitudinal fasciculus (MLF)]. The present study evaluated the temporal characteristics of the facilitatory effect of amygdaloid stimulation on startle elicited electrically from different points along the acoustic startle pathway. A single 0.1-msec pulse was delivered to the central nucleus of the amygdala at various times before the onset of a 1-msec pulse in various sites in the startle pathway. The shortest amygdaloid stimulation-startle onset interval to significantly enhance startle was 0 msec for the VCN, 2 msec for the PLZ, 3 msec for the RPC and 7 msec for the MLF. These results indicate that amygdaloid stimulation enhances electrically elicited startle in a temporal manner that is complementary to facilitation of acoustic startle. The similarity of amygdala-stimulated enhancement and fear potentiation of electrically elicited startle is also discussed.
authors: Department of Psychiatry, Yale University, New Haven, CT 06508.
authors: J B
authors: JB
authors: Rosen
authors: M
authors: M
authors: Davis
mesh_terms: D000161:Acoustic Stimulation; D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001143:Arousal / Q000502:physiology*; D001306:Auditory Pathways / Q000502:physiology; D001931:Brain Mapping; D003056:Cochlear Nerve / Q000502:physiology; D004558:Electric Stimulation; D005239:Fear / Q000502:physiology*; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009847:Olivary Nucleus / Q000502:physiology; D011149:Pons / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013216:Reflex, Startle / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology