Fear, conditioned

Matsuzawa S, Suzuki T, Misawa M Involvement of mu-opioid receptor in the salsolinol-associated place preference in rats exposed to conditioned fear stress. Alcohol Clin Exp Res 24 366-372, 2000... 

Yoshioka, M, Matsumoto, M, Togashi, H and Saito, H (1995) Effects of conditioned fear stress on 5-HT release in the rat prefrontal cortex. Pharmacol. Biochem. Behav. 51 515-519. 

Fear-potentiated startle reflex (conditioned fear)... 

Ledgerwood L, Richardson R, Cranney J (2004) d-Cycloserine and the facilitation of extinction of conditioned fear consequences for reinstatement. Behav Netuosci 118 505-513... 

Montkowski A, Poettig M, Mederer A, Holsboer F (1997) Behavioural performance in three substrains of mouse strain 129. Brain Res 762 12-18 Morgan MA, LeDoux JE (1995) Differential contribution of dorsal and ventral medial prefrontal cortexto the acquisition and extinction of conditioned fear in rats. Behav Neurosci... 

Morrow BA, Elsworth JD, Rasmusson AM, Roth RH (1999) The role of mesoprefrontal dopamine netuons in the acquisition and expression of conditioned fear in the rat. Neuroscience 92 553-564... 

Vanderwolf CH, Cain DP (1994) The behavioral neurobiology of learning and memory a conceptual reorientation. Brain Res Brain Res Rev 19 264-297 Villarreal DM, Do V, Haddad E, Derrick BE (2002) NMDA receptor antagonists sustain LTP and spatial memory active processes mediate LTP decay. Nat Neurosci 5 48-52 Walker DL, Ressler KJ, Lu KT, Davis M (2002) Facilitation of conditioned fear extinction by systemic administration or intra-amygdala infusions of d-cycloserine as assessed with fear-potentiated startle in rats. J Neurosci 22 2343-2351 Wallenstein GV, Eichenbaum H, Hasselmo ME (1998) The hippocampus as an associator of discontiguous events. Trends Neurosci 21 317-323 Wehner JM, Radcliffe RA, Bowers BJ (2001) Quantitative genetics and mouse behavior. Annu Rev Neurosci 24 845-867... 

Referred to as a conditioned fear paradigm, the fear potentiated startle response was first described by Brown et al. (1951). In the original test, an acoustic stimulus is presented in the presence of a conditioned stimulus that has previously been paired with an aversive, unconditioned stimulus. The amplitude of the acoustic startle response is thought to indicate the degree of conditioned anxiety, which can be reduced by anxiolytic drugs (Davis et al. 1993 Hijzen et al. 1995). 

Hashimoto S, Inoue T, Koyama T (1999) Effects of conditioned fear stress on serotonin neurotransmission and freezing behavior in rats. Eur J Pharmacol 378 23-30 Hayley S, Borowski T, Merali Z, Anisman H (2001) Central monoamine activity in genetically distinct strains of mice following a psychogenic stressor effects of predator exposure. Brain Res 892 293-300... 

Inoue T, Koyama T, Yamashita I (1993) Effect of conditioned fear stress on serotonin metabolism in the rat brain. Pharmacol Biochem Behav 44 371-374 Inoue T, Tsuchiya K, Koyama T (1994) Regional changes in dopamine and serotonin activation with various intensity of physical and psychological stress in the rat brain. Pharmacol Biochem Behav 49 911-920... 

When the CS is presented repeatedly in the absence of the US, a reduction in the condition fear response occurs. This process is called extinction. It forms the basis for exposure-based psychotherapies for the treatment of anxiety disorders characterized by exaggerated fear responses. Individuals who show an abihty to quickly attenuate learned fear through a powerful and efficient extinction processes are hkely to fimction more effectively under dangerous conditions. 

Stressful stimuli of many types produce marked increases in brain noradrenergic function. Stress produces regional selective increases in NE turnover in the locus coeruleus (LC), limbic regions (hypothalamus, hippocampus, and amygdala), and cerebral cortex. These changes can be elicited with immobilization stress, foot-shock stress, tail-pinch stress, and conditioned fear. Exposure to stressors from which the animal cannot escape results in behavioral deficits termed learned helplessness. The learned helplessness state is associated with depletion of NE, probably reflecting the point where synthesis cannot keep up with demand. These studies have been reviewed elsewhere in detail (Bremner et al. 1996a,b). 

Few studies have examined noradrenergic function in patients with phobic disorders. In patients with specific phobias, increases in subjective anxiety and increased heart rate, blood pressure, plasma NE, and epinephrine have been associated with exposure to the phobic stimulus (Nesse et al. 1985). This finding may be of interest from the standpoint of the model of conditioned fear, reviewed above, in which a potentiated release of NE occurs in response to a reexposure to the original stressful stimulus. Patients with social phobia have been found to have greater increases in plasma NE in comparison to healthy controls and patients with panic disorder (Stein et al. 1992). In contrast to panic disorder patients, the density of lymphocyte a-adrenoceptors is normal in social phobic patients (Stein et al. 1993). The growth hormone response to intravenous clonidine (a marker of central a2-receptor function) is blunted in social phobia patients (Tancer et al. 1990). 

Cain C, Blouin A, Barad MG (2002) L-type voltage-gated calcium channels are required for extinction but not for acquisition or expression, of conditional fear in mice. J Neurosci 22 9113-9121... 

McGaugh JL, Roozendaal B (2002) Role of adrenal stress hormones in forming lasting memory in the brain. Curr Opin Neurobiol 12 205-210 McGaugh JL, Castellano C, Brioni J (1990) Picrotoxin enhances latent extinction of conditioned fear. Behav Neurosci 104 264-267... 

Anxiety represents a state of heightened vigilance and fear, but pathological anxiety can be distinguished from fear in that it is inappropriately evoked and may persist in the absence of real threat or danger. The study of conditioned fear has provided detailed information on the neural circuitry and intracellular mechanisms that are important to fear responses and their long-term retention. The description of neural circuitry and the mechanisms underlying disorders of fear memory such as posttraumatic stress disorder (PTSD) may also be relevant to other anxiety states that share common neural substrates. 

Goosens K, Holt W, Maren S (2000) A role for amygdaloid PKA and PKC in the acquisition of long-term conditional fear memories in rats. Behav Brain Res 114 145-152... 

Sweat J (2001) The nem-onal MAP kinase cascade a biochemical signal integration system subserving synaptic plasticity and memory. J Neurochem 76 1-10 Szapiro G, Vianna MRM, McGaugh JL, Medina JH, Izquierdo 1 (2003) The role of NMDA glutamate receptors, PKA, MAPK, and CAMKll in the hippocampus in extinction of conditioned fear. Hippocampus 13 53-58... 

Izumi T, Inoue T, Tsuchiya K, Hashimoto S, Ohmori T, Koyama T (1996) Effect of the selective CCKB receptor antagonist LY288513 on conditioned fear stress in rats. Eur J Pharmacol 300 25-31... 

StrOhle A, Pasini A, Romeo E, Hermann B, Spalletta G, di Michele F, Holsboer F, Rupprecht R (2000) Fluoxetine decreases concentrations of 3a,5a-tetrahydrodeoxycorticosterone (3a,5a-THDOC) in major depression. J Psychiatr Res 34 183-186 StrOhle A, Kellner M, Holsboer F, Wiedemann K (2001) Anxiolytic activity of atrial natriuretic peptide in patients with panic disorder. Am J Psychiatry 158 1514-1516 StrOhle A, Romeo E, di Michele F, Pasini A, Yassouridis A, Holsboer F, Rupprecht R (2002) GABAA receptor modulatory neuroactive steroid composition in panic disorder and during paroxetine treatment. Am J Psychiatry 159 145-147 StrOhle A, Romeo E, di Michele F, Pasini A, Hermann B, Gajewsky G, Holsboer F, Rupprecht F (2003) Induced panic attacks shift GABAA receptor modulatory neuroactive steroid composition. Arch Gen Psychiatry 60 161-168 Szapiro G, Vianna MRM, McGaugh JL, Medina JH, Izquierdo I (2003) The role of NMDA glutamate receptors, PKA, MAPK, and CAMKII in the hippocampus in extinction of conditioned fear. Hippocampus 13 53-58... 

LaBar, K.S., Gatenby, J.C., LaBar, K.S., Gatenby, J.C., Gore, J.C., LeDoux, J.E., and Phelps, E.A. (1998) Human amydala activation during conditioned fear acquisition and extinction a mixed-trial fMRI study. Neuron 20 937-945. 

LeDoux, Joseph E., Jiro Iwata, Piera Cicchetti, and Donald J. Reis. 1988. "Different Projections of the Central Amygdaloid Nucleus Mediate Autonomic and Behavioral Correlates of Conditioned Fear." Journal of Neuroscience 8 2517-29. 

In most humans in most contemporary societies, the quick and dirty path is relatively unimportant. Success and survival do not turn heavily on split-second decisions. Instead, decisions and the concomitant emotions depend crucially on prior cognitive processing of the situation. In animals other than humans, it is often difficult to decide whether what looks like an emotional reaction is triggered by a mental representation of the situation or whether it is merely a learned response. The apparent guilt of the dog that has shredded the newspaper in its owner s absence may simply be a conditioned fear of punishment, since the same response is produced when the owner himself shreds the newspaper and leaves it on the floor (Vollmer 1977). 

Logue, S. F., Paylor, R. and Wehner, J. M. (1997) Hippocampal lesions cause learning deficits in inbred mice in the Morris water maze and conditioned-fear task. Behav Neurosci 111, 104-113. 

Otagiri, A., Wakabayashi, I. Shibasaki, T. (2000). Selective corticotropin-releasing factor type 1 receptor antagonist blocks conditioned fear-induced release of noradrenaline in the hypothalamic paraventricular nucleus of rats. J. Neuroendocrinol., 12, 1022-1026. 

Yokoo, H., Tanaka, M., Yoshida, M., Tsuda, A., Tanaka, T. Mizoguchi, K. (1990b). Direct evidence of conditioned fear-elicited enhancement of noradrenaline release in the rat hypothalamus assessed by intracranial microdialysis. Brain Res., 536,305-308. 

Akirav, I., Raizel, H., and Maroun, M. (2006). Enhancement of conditioned fear extinction by infusion of the GABAA agonist muscimol into the rat prefrontal cortex and amygdala. Eur.J. Neurosci 23,... 

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