Topic: periaqueductal gray

Instinctive behaviours, such as hunting and defense, are part of the natural repertoire of behaviours that are shaped by evolution and critical for the survival of both individual and species. The midbrain periaqueductal gray (PAG) has emerged as a bottleneck in the routing of most instinctive behaviours, translating sensory and cognitive information into an appropriate motor response. Yet, the exact mechanisms of this translation remain elusive. We aimed to identify the neural circuits in the brainstem bridging the initiation and execution of instinctive behaviours in mice by developing an an

Pain is an adaptive and primordial aspect of mammal’s physiology whose role is to warn against potential harmful situations and prevent aggravation of actual physical damages. However, many patients suffer from chronic pain, which overpasses pain’s adaptive trait becoming pathological. Nociceptive signal transmission is first relayed by the spinal cord before reaching the brain through ascending pathways. The control of spinal integration descending pathway is orchestrated by the periaqueductal gray (PAG) and rostral ventromedial medulla (RVM). In the RVM, ON, OFF and neutral cells, are respec

In order to survive, animals must precisely regulate their approach and defensive behaviors towards threats. The periaqueductal gray (PAG), particularly its dorsal division, is a key hub in the innate defensive system, transforming sensory information into coordinated defensive motor responses. Neurons within the dorsal PAG exhibit distinct functional activity in relation to certain behaviors, and cells tuned to approach and escape from various threats have been reported. Despite its significance, the cellular and neurochemical identity underlying the functional heterogeneity of PAG neurons is

While straightforward monitoring and ethological interpretability has made behavior the most commonly used parameter for inferring and characterizing emotional states in animals, there is a long history of cardiac readouts as emotion indicators in the fields of neurosciences and psychology.Conceptual frameworks such as the threat imminence theory, postulating that the distance to a threat influences the selection of a defensive strategy, defined a convincing model to explain the range of possible behavioral responses. However, while autonomic responses proved equally variable and dynamic, ther

Defensive brain states, such as fear and anxiety, evolved as mediators of multidimensional reactions to threat, which encompass integrated autonomic, behavioral and endocrine responses. Multiple interconnected brain structures have been involved in defensive reactions, in particular the midbrain’s periaqueductal gray (PAG), the amygdala, and different cortical areas such as the auditory and prefrontal cortices, together processing information at multiple levels of the neuraxis. Several roles pertaining to higher-order threat processing have been assigned to the medial prefrontal cortex (mPFC),

Instinctive behaviours such as defence, feeding and reproduction have evolved across animal phyla and ensure survival of both the individual and its kin. A brainstem region central to the initiation of virtually all instinctive behaviours is the periaqueductal gray (PAG). Although stereotyped to some degree, the expression of instinctive behaviours exhibits significant variability within and across individuals. Previous work has mostly focussed on behavioural variability arising from plasticity mechanisms occurring in forebrain regions projecting to the PAG, including the hypothalamus, amygdal

Proper coordination of organ function with behavioral actions is crucial for survival. In response to an emerging threat, energy must be rapidly distributed to the muscles to ensure rapid flight. When the body is overtaxed, an animal may shut off all but the most crucial behaviors. This bidirectional balance of motor programs with the internal body state is mediated by complex interactions between the autonomic and central nervous systems. To untangle these interactions, we utilize the larval zebrafish by taking advantage of its optical transparency and small size to combine brain-wide imaging

Contextual fear learning is a mental process, during which an originally neutral context becomes associated with a threat. Previous data have shown that one of the main controlling units of the defensive system, the central amygdala (CeA) is an active participant of contextual fear learning. Recently we showed that vasoactive intestinal polypeptide (VIP)-expressing neurons in the periaqueductal gray and dorsal raphe that innervate the CeA play a role in contextual fear acquisition, but not in the recall. As the primary source of contextual information is the hippocampus, we aimed to uncover th