Biopsy samples from patients with irritable bowel syndrome, but not from those with mastocytosis or unspecific gastrointestinal complaints reveal unique nerve activation in all gut regions independent of mast cell density, histamine content or specific gastrointestinal symptoms.

Introduction: We previously showed enteric nerve activation after application of colonic mucosal biopsy supernatants from patients with irritable bowel syndrome (IBS). The question remains whether this is a region-specific or a generalized sensitization. We tested the nerve-activating properties of supernatants from large and small intestinal regions of IBS patients with diarrhea (IBS-D) in comparison to those from mastocytosis patients with diarrhea (MC-D) or non-IBS/non-MC patients with GI-complaints.

Calcium Imaging of Nerve-Mast Cell Signaling in the Human Intestine.

It is suggested that an altered microenvironment in the gut wall alters communication along a mast cell nerve axis. We aimed to record for the first time signaling between mast cells and neurons in intact human submucous preparations. We used the Ca sensitive dye Fluo-4 AM to simultaneously image changes in intracellular calcium [Ca] (%ΔF/F) in neurons and mast cells.

Representation of three-dimensional space in the auditory cortex of the echolocating bat P. discolor.

The auditory cortex is an essential center for sound localization. In echolocating bats, combination sensitive neurons tuned to specific delays between call emission and echo perception represent target distance. In many bats, these neurons are organized as a chronotopically organized map of echo delay.

Echo-acoustic flow shapes object representation in spatially complex acoustic scenes.

Echolocating bats use echoes of their sonar emissions to determine the position and distance of objects or prey. Target distance is represented as a map of echo delay in the auditory cortex (AC) of bats. During a bat's flight through a natural complex environment, echo streams are reflected from multiple objects along its flight path.

Congruent representation of visual and acoustic space in the superior colliculus of the echolocating bat Phyllostomus discolor.

The midbrain superior colliculus (SC) commonly features a retinotopic representation of visual space in its superficial layers, which is congruent with maps formed by multisensory neurons and motor neurons in its deep layers. Information flow between layers is suggested to enable the SC to mediate goal-directed orienting movements. While most mammals strongly rely on vision for orienting, some species such as echolocating bats have developed alternative strategies, which raises the question how sensory maps are organized in these animals.

Echo-acoustic flow affects flight in bats.

Flying animals need to react fast to rapid changes in their environment. Visually guided animals use optic flow, generated by their movement through structured environments. Nocturnal bats cannot make use of optic flow, but rely mostly on echolocation.