Search results for "Amygdala"

Immature excitatory neurons develop during adolescence in the human amygdala.

2019

The human amygdala grows during childhood, and its abnormal development is linked to mood disorders. The primate amygdala contains a large population of immature neurons in the paralaminar nuclei (PL), suggesting protracted development and possibly neurogenesis. Here we studied human PL development from embryonic stages to adulthood. The PL develops next to the caudal ganglionic eminence, which generates inhibitory interneurons, yet most PL neurons express excitatory markers. In children, most PL cells are immature (DCX+PSA-NCAM+), and during adolescence many transition into mature (TBR1+VGLUT2+) neurons. Immature PL neurons persist into old age, yet local progenitor proliferation sharply d…

Cannabinoid CB1 receptors in distinct circuits of the extended amygdala determine fear responsiveness to unpredictable threat.

2016

The brain circuits underlying behavioral fear have been extensively studied over the last decades. Although the vast majority of experimental studies assess fear as a transient state of apprehension in response to a discrete threat, such phasic states of fear can shift to a sustained anxious apprehension, particularly in face of diffuse cues with unpredictable environmental contingencies. Unpredictability, in turn, is considered an important variable contributing to anxiety disorders. The networks of the extended amygdala have been suggested keys to the control of phasic and sustained states of fear, although the underlying synaptic pathways and mechanisms remain poorly understood. Here, we…

Activation of MORs in the VTA induces changes on cFos expression in different projecting regions: Effect of inflammatory pain.

2019

Abstract Chronic pain is a worldwide major health problem and many pain-suffering patients are under opioid based therapy. Epidemiological data show that pain intensity correlates with the risk of misuse of prescription opioids, and other drugs of abuse including alcohol. This increased vulnerability to suffer Substance Use Disorders could be, in part, caused by functional changes that occur over the mesocorticolimbic system, a brain pathway involved in reward processing and addiction. Previous data in rats revealed that inflammatory pain desensitizes mu opioid receptors (MORs) in the ventral tegmental area (VTA). As a consequence, pain alters dopamine release in the nucleus accumbens (NAc)…

Mismatch or allostatic load? Timing of life adversity differentially shapes gray matter volume and anxious temperament

2015

Traditionally, adversity was defined as the accumulation of environmental events (allostatic load). Recently however, a mismatch between the early and the later (adult) environment (mismatch) has been hypothesized to be critical for disease development, a hypothesis that has not yet been tested explicitly in humans. We explored the impact of timing of life adversity (childhood and past year) on anxiety and depression levels (N = 833) and brain morphology (N = 129). Both remote (childhood) and proximal (recent) adversities were differentially mirrored in morphometric changes in areas critically involved in emotional processing (i.e. amygdala/hippocampus, dorsal anterior cingulate cortex, res…

2018

Projections from the central nucleus of the amygdala (CEA) into the lateral hypothalamic area (LHA) show a very complex pattern. After injection of an anterograde tracer (Phaseolus vulgaris leucoagglutinin – PHAL) into several parts of the CEA, we observed that projections converged onto the caudal lateral LHA but provided distinct patterns in rostral tuberal regions. These projections were compared to that of neurons containing the peptides ‘melanin-concentrating hormone’ (MCH) or hypocretin (Hcrt). Because the distribution of these neurons is stereotyped, it was possible to characterize distinct divisions into the LHA. Some of them in the rostral tuberal LHA (the dorsal (LHAd) and suprafo…

Synchronized Activity in The Main and Accessory Olfactory Bulbs and Vomeronasal Amygdala Elicited by Chemical Signals in Freely Behaving Mice

2017

AbstractChemosensory processing in mammals involves the olfactory and vomeronasal systems, but how the activity of both circuits is integrated is unknown. In our study, we recorded the electrophysiological activity in the olfactory bulbs and the vomeronasal amygdala in freely behaving mice exploring a battery of neutral and conspecific stimuli. The exploration of stimuli, including a neutral stimulus, induced synchronic activity in the olfactory bulbs characterized by a dominant theta rhythmicity, with specific theta-gamma coupling, distinguishing between vomeronasal and olfactory structures. The correlated activation of the bulbs suggests a coupling between the stimuli internalization in t…

The Role of Anabolic Androgenic Steroids in Disruption of the Physiological Function in Discrete Areas of the Central Nervous System

2017

: Anabolic-androgenic steroids (AAS) abuse is often associated with a wide spectrum of adverse effects. These drugs are frequently abused by adolescents and athletes for esthetic purposes, as well as for improvement of their endurance and performances. In this literature review, we evaluated the correlation between AAS and anxiety or aggression. Two pathways are thought to be involved in AAS-induced behavioral disorders. Direct pathway via the amygdalo-fugal pathway, which connects the central nucleus of the amygdala to the brainstem, is involved in cognitive-emotive and homeostatic processes. The latter is modified by chronic AAS use, which subsequently leads to increased anxiety. Indirect…

Comparative Distribution of Relaxin-3 Inputs and Calcium-Binding Protein-Positive Neurons in Rat Amygdala

2016

The neural circuits involved in mediating complex behaviors are being rapidly elucidated using various newly developed and powerful anatomical and molecular techniques, providing insights into the neural basis for anxiety disorders, depression, addiction, and dysfunctional social behaviors. Many of these behaviors and associated physiological processes involve the activation of the amygdala in conjunction with cortical and hippocampal circuits. Ascending subcortical projections provide modulatory inputs to the extended amygdala and its related nodes (or “hubs”) within these key circuits. One such input arises from the nucleus incertus (NI) in the tegmentum, which sends amino acid- and pepti…

Afferent and efferent projections of the anterior cortical amygdaloid nucleus in the mouse

2017

The anterior cortical amygdaloid nucleus (ACo) is a chemosensory area of the cortical amygdala that receives afferent projections from both the main and accessory olfactory bulbs. The role of this structure is unknown, partially due to a lack of knowledge of its connectivity. In this work, we describe the pattern of afferent and efferent projections of the ACo by using fluorogold and biotinylated dextranamines as retrograde and anterograde tracers, respectively. The results show that the ACo is reciprocally connected with the olfactory system and basal forebrain, as well as with the chemosensory and basomedial amygdala. In addition, it receives dense projections from the midline and posteri…

Afferent and Efferent Connections of the Cortex-Amygdala Transition Zone in Mice

2016

The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, it receives projections from the main and accessory olfactory bulbs. In this work we have studied the pattern of afferent and efferent projections of the CxA, which are mainly unknown, by using the retrograde tracer Fluorogold and the anterograde tracer biotinylated dextranamine. The results show that …