title: Neuronal correlates of sustained fear in the anterolateral part of the bed nucleus of stria terminalis.
abstract: As part of the extended amygdala network, the bed nucleus of the stria terminalis (BNST) was shown to be critically involved in processing sustained fear responses to diffuse and unpredictable threats. However, neuronal activity patterns in relation to sustained components of the fear response remain elusive, so far. We used a fear training paradigm with unpredictable pairing of conditioned and unconditioned stimuli allowing distinction between phasic and sustained components of conditioned fear, and recorded single units in the anterolateral part of the BNST (BNSTal) in freely behaving mice. An objective, non-biased cluster-analysis was performed for each identified single unit on specific waveform-, activity-, stimulus-dependent and LFP-related parameters. The analysis revealed three distinct neuronal subpopulations of biphasic-, sustained fear on- and fear off-neurons. Results show that activities of biphasic- and sustained fear on-neurons temporally coincide with the shift from phasic to sustained components of the fear response. Presentation of non-conditioned auditory stimuli resulted in a variety of neuronal responses in BNSTal with no indication of biphasic response profiles. It is suggested that fear conditioning sharpens neuronal response profiles in BNSTal with biphasic-cells signaling phasic and sustained fear. These results confirm the pivotal role of BNST in processing sustained fear on the neuronal level, thereby complementing pharmacological experimental animal and human imaging data.
authors.affiliation: Institute of Physiology I, Westfälische Wilhelms-University Münster, D-48149 Münster, Germany.
authors.forename: Thiemo
authors.initials: T
authors.lastname: Daldrup
authors.affiliation: Institute of Physiology I, Westfälische Wilhelms-University Münster, D-48149 Münster, Germany. Electronic address: lesting@uni-muenster.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Lesting
authors.affiliation: Department of Neurology, Westfälische Wilhelms-University Münster, D-48149 Münster, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Meuth
authors.affiliation: Institute of Physiology I, Westfälische Wilhelms-University Münster, D-48149 Münster, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Seidenbecher
authors.affiliation: Institute of Physiology I, Westfälische Wilhelms-University Münster, D-48149 Münster, Germany. Electronic address: papechris@ukmuenster.de.
authors.forename: Hans-Christian
authors.initials: HC
authors.lastname: Pape
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D055724:Electrophysiological Phenomena; D005239:Fear / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000502:physiology*; D012686:Septal Nuclei / Q000502:physiology*
keywords: Anxiety; Bed nucleus of stria terminalis; Electrophysiology; Extended amygdala; Freely behaving; Phasic fear