pre pulse inhibition acoustic startle reflex  (Med Associates Inc)

Journal: Cell

Article Title: The Basolateral Amygdala Is Essential for Rapid Escape: A Human and Rodent Study

doi: 10.1016/j.cell.2018.09.028

Figure Lengend Snippet: BLA Damage Leads to Over-potentiation of the ASR during Anticipation of Imminent yet Escapable Threat (A) Participants in the TET saw pictures that could “attack” by a rapid approach, during which only a sufficiently fast button press could provide escape. Escape failure resulted in aversive shock stimulus (AS) presentation. Distance and attack speed were manipulated to be distant (easily escapable), imminent (with effort escapable at chance level), or inescapable, and all threat conditions (yellow pictures with shock hazard icon) were compared to an equivalent control condition (blue pictures with neutral icon) but without the threat of AS exposure. Note that this timing adjustment renders escape reaction time an uninformative behavioral measure, but it ensures that our measure of interest, acoustic startle reflex (ASR), is unaffected by the participant’s general ability in reaction speed. (B) During the anticipation phase, ASR was measured. See and Figure S1 . (C) Estimated marginal means of the three-way—condition (threat and safe), distance (distant, imminent, and inescapable), group (BLA-damaged and healthy control)—interaction (Wald χ 2 = 10.023; p = 0.040) of ASR magnitudes in the TET (BLA damage, n = 5; HC, n = 14). This interaction reveals reliable threat potentiation in imminent (Wald χ 2 = 29.972; p < 0.001) and inescapable (Wald χ 2 = 42.270; p < 0.001), but not in distant (Wald χ 2 = 2.003; p = 0.157), conditions. Crucially, imminent threat potentiation was significantly stronger in BLA-damaged subjects (Wald χ 2 = 6.191; p = 0.013) and, although HCs showed significantly lower threat potentiation in imminent compared to inescapable conditions (Wald χ 2 = 4.670; p = 0.031), this was not the case in BLA-damaged subjects (Wald χ 2 = 0.196; p = 0.658). ∗ p < 0.05; ∗∗ p < 0.01; ∗∗∗ p < 0.001; see for corresponding potentiation values and confidence intervals. Error bars represent standard error of the mean.

Article Snippet: Acoustic Startle Reflex Package for Rat , Med Associates, St. Albans, VT, USA , Cat#MED-ASR-PRO1.

Techniques: Control

Journal: Cell

Article Title: The Basolateral Amygdala Is Essential for Rapid Escape: A Human and Rodent Study

doi: 10.1016/j.cell.2018.09.028

Figure Lengend Snippet: BLA Neuronal Downregulation Induces Passive Defensive Reactions upon Imminent Threat (A) Virus injection site and expression of hM4D revealed by mCherry immunohistochemistry. Scale bar, 200 μM. (B) (Left) Example traces of action potentials fired during 400-ms incremental current injections (from −100 pA to 300 pA; red trace representing 200 pA; see inset) before (top) and during CNO treatment (bottom). (Right) Mean action potential frequency as function of current injected before CNO (black) and during CNO (purple) is shown. (C) Experimental design for the TET and ASR assessment: day 1, TET conditioning; day 2, TET testing with vehicle (n = 6, gray) or CNO (n = 7, purple) intraperitoneal (i.p.) injected in the BLA 30 min prior to (1) exposure in threat and escape task (TET) to distant (4 kHz, yellow), imminent (12 kHz, orange), or inescapable (12 kHz, red; in separate experiment) threat. (i) “No escape” illustrates shuttling only upon foot shock exposure; (ii) “escape” illustrates avoidance of foot shock by shuttling before end of tone. (2) Acoustic startle response measured after exposure to 4- or 12-kHz tones followed by white noise burst on day 8 (ASR habituation), followed on day 9 by TET recall, and on day 10 by ASR 30 min after vehicle (gray) or CNO (purple) i.p. injection. (D and E) CNO (purple) as compared to vehicle (gray) i.p. injections in hM4D-infected rats that were exposed to imminent threat (D) reduced escape responses (two-way ANOVA: treatment × threat imminence; F (1, 22) = 19.48; p < 0.001) and (E) increased freezing levels (two-way ANOVA: treatment effect; F (1, 22) = 16.69; p < 0.001). Imminent threat induces significantly more freezing compared to distant threat in rats injected with CNO compared to Veh (imminence effect F (1, 22) = 5.06; p < 0.05). CNO has no effects on freezing after inescapable threats. (F) CNO enhanced the potentiation of the startle reflex (ASR; two-way ANOVA: treatment × threat imminence; F (1, 20) = 10.21; p < 0.01; n = 6 each group) that occurs upon exposure to imminent, but not to distant or inescapable, threats. Data from TET test conducted under naive conditions and vehicle treatments were pooled and converted to percent escape behavior and were normally distributed (D’Agostino and Pearson normality test; for distant threat, K 2 = 5.40, p = 0.06; for imminent threat, K 2 = 1.11, p = 0.57). ∗∗ p < 0.01; ∗∗∗ p < 0.001. Error bars represent standard error of the mean. See also and .

Article Snippet: Acoustic Startle Reflex Package for Rat , Med Associates, St. Albans, VT, USA , Cat#MED-ASR-PRO1.

Techniques: Virus, Injection, Expressing, Immunohistochemistry, Infection

Journal: Cell

Article Title: The Basolateral Amygdala Is Essential for Rapid Escape: A Human and Rodent Study

doi: 10.1016/j.cell.2018.09.028

Figure Lengend Snippet: Combining TET with Chemogenetic Inhibition of BLA, Related to Figure 4 (A) Representative examples of viral expression in the BLA (in rostro-caudal order) after injection with AAV-CaMKIIα-hM4D-mCherry. Viral expression frequently extended somewhat beyond the LA laterally and dorsally and included parts of the dorsal endopiriform nucleus. (B) Pink areas represent the minimum (darker color) and the maximum (lighter color) expression of AAV-CaMKIIα-hM4D-mCherry (C) Four weeks after virus injection rats were conditioned on day 1 in the TET to establish baseline value (“Bas”) and then tested on day 2 (“Inj”) 30 min after Vehicle (“hM4D Veh,” gray) or CNO injection (“hM4D CNO,” orange). (D) We found no differences between groups in baseline escape to distant threats. downregulation of the BLA did not affect escape responses to distant threat. (E) Decrease of escape response to imminent threat after BLA inactivation (two-way RM ANOVA: treatment x time effect, F (2, 22) = 24.29, p < 0.001). After 24 hours from injection (post), this effect was still present to a lesser extent. No baseline differences between groups in escape responses to imminent threat. (F) CNO injection increased latency to escape both to distant (unpaired t test, t = 0.01 df = 11, p = 3.01) and imminent (unpaired t test, t = 0.006 df = 11, p = 3.31) threats (G) Time course showing that over several trials BLA inactivation did not affect freezing reaction to distant threat. (H) Time course overall several trials showing that downregulation of the BLA increased freezing levels to imminent threat (two-way RM ANOVA: treatment x time effect, F (14, 154) = 2.88, p < 0.01). (I) CNO did not induce any change of freezing behavior after the presentation of inescapable threats (F (1, 10) = 0.01, p = 0.90). (J) Baseline amplitude of startle reflex following Veh or CNO injection (unpaired t test, t = 0.29 df = 10, p = 0.77). ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001 (K) CNO did not induce any gross locomotor deficit in hM4D-injected and naive rats, compared to Veh rats ( F (3, 22) = 0.826, p = 0.85). (L) CNO treatment in naive rats did not induce any impairment in escape behavior to distant and imminent threats compared to veh-treated rats (two-way ANOVA: treatment, F (1, 18) = 0.49, p = 0.48).

Article Snippet: Acoustic Startle Reflex Package for Rat , Med Associates, St. Albans, VT, USA , Cat#MED-ASR-PRO1.

Techniques: Inhibition, Expressing, Injection, Virus

Journal: Cell

Article Title: The Basolateral Amygdala Is Essential for Rapid Escape: A Human and Rodent Study

doi: 10.1016/j.cell.2018.09.028

Figure Lengend Snippet: Activation of Oxytocin-Sensitive Neurons during Downregulation of the BLA Rescues the Switch between Active and Passive Responses to Imminent Threat (A) Rats treated with i.p. injection of vehicle (gray) or CNO to inhibit the BLA (purple) received 15 min later either vehicle (gray) or TGOT (blue) by i.c. injection into the CeL 15 min before tested in the TET. Vehicle and vehicle, n = 6; CNO and vehicle, n = 8; CNO and TGOT, n = 8. (B) TGOT rescued the escape deficit to imminent threat induced by CNO-mediated inactivation of the BLA (two-way ANOVA: imminence effect F (1, 36) = 48.91, p < 0.001; treatment effect F (2, 36) = 9.44, p < 0.001). Escape to distant threat was unaffected by CNO or TGOT. ∗∗ p < 0.01. (C) TGOT abolished the potentiation of acoustic startle to imminent threat obtained by CNO-induced inactivation of the BLA (two-way ANOVA: imminence × treatment effect F (2, 30) = 4.21; p < 0.05). Neither CNO nor TGOT affected startle potentiation by distant threat. ∗ p < 0.05. (D) CNO-increased freezing to imminent threat reverted back to vehicle levels after TGOT (two-way ANOVA: imminence effect F (1, 32) = 7.02, p < 0.05; treatment effect F (2, 32) = 6.89, p < 0.01). Neither CNO nor TGOT affected freezing to distant threat. ∗ p < 0.05. (E) Potentiation of the acoustic startle to imminent threats was inversely correlated to escape proficiency ( r = −0.58; p = 0.01; n = 18). (F) Localization of microinjectors tips for each animal according to brain atlas of . Error bars represent standard error of the mean. See also Figure S6 .

Article Snippet: Acoustic Startle Reflex Package for Rat , Med Associates, St. Albans, VT, USA , Cat#MED-ASR-PRO1.

Techniques: Activation Assay, Injection

Journal: Cell

Article Title: The Basolateral Amygdala Is Essential for Rapid Escape: A Human and Rodent Study

doi: 10.1016/j.cell.2018.09.028

Figure Lengend Snippet:

Article Snippet: Acoustic Startle Reflex Package for Rat , Med Associates, St. Albans, VT, USA , Cat#MED-ASR-PRO1.

Techniques: Virus, Plasmid Preparation, Recombinant, Software