title: Glucocorticoid programing of the mesopontine cholinergic system.
abstract: Stress perception, response, adaptation, and coping strategies are individually distinct, and the sequel of stress and/or glucocorticoids (GCs) is also distinct between subjects. In the last years, it has become clear that early life stress is a powerful modulator of neuroendocrine stress-responsive circuits, programing intrinsic susceptibility to stress, and potentiating the appearance of stress-related disorders such as depression, anxiety, and addiction. Herein we were interested in understanding how early life experiences reset the normal processing of negative stimuli, leading to emotional dysfunction. Animals prenatally exposed to GCs (in utero glucocorticoid exposure, iuGC) present hyperanxiety, increased fear behavior, and hyper-reactivity to negative stimuli. In parallel, we found a remarkable increase in the number of aversive 22 kHz ultrasonic vocalizations in response to an aversive cue. Considering the suggested role of the mesopontine tegmentum cholinergic pathway, arising from the laterodorsal tegmental nucleus (LDT) and pedunculopontine tegmental nucleus (PPT), in the initiation of 22 kHz vocalizations and hypothetically in the control of emotional arousal and tone, we decided to evaluate the condition of this circuit in iuGC animals. Notably, in a basal situation, iuGC animals present increased choline acetyltransferase (ChAT) expression in the LDT and PPT, but not in other cholinergic nuclei, namely in the nucleus basalis of Meynert. In addition, and in accordance with the amplified response to an adverse stimulus of iuGC animals, we found marked changes in the cholinergic activation pattern of LDT and PPT regions. Altogether, our results suggest a specific cholinergic pathway programing by prenatal GC, and hint that this may be of relevance in setting individual stress vulnerability threshold.
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Sónia
authors.initials: S
authors.lastname: Borges
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Coimbra
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Carina
authors.initials: C
authors.lastname: Soares-Cunha
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Ventura-Silva
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Luisa
authors.initials: L
authors.lastname: Pinto
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Miguel M
authors.initials: MM
authors.lastname: Carvalho
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: José-Miguel
authors.initials: JM
authors.lastname: Pêgo
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Ana João
authors.initials: AJ
authors.lastname: Rodrigues
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho , Braga , Portugal ; ICVS/3B's - PT Government Associate Laboratory , Braga/Guimarães , Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Sousa
keywords: acetylcholine; anxiety; fear; glucocorticoids; laterodorsal tegmental nucleus; pedunculopontine tegmental nucleus; stress; ultrasonic vocalizations