Dissecting the gut-brain axis It is generally believed that cells in gut transduce sensory information through paracrine action of hormones. Kaelberer et al. found that, addition to well-described classical transduction, enteroendocrine also form fast, excitatory synapses with vagal afferents (see Perspective by Hoffman and Lumpkin). This more direct circuit for signaling uses glutamate as a neurotransmitter. Thus, cues stimulate could potentially be manipulated influence specific brain...

Behavioral sensitization of the gill-withdrawal reflex Aplysia is caused by presynaptic facilitation at synapses mechanoreceptor sensory neurons onto motor and interneurons. The has been shown to be simulated serotonin (the putative facilitatory transmitter) cyclic AMP accompanied an increase in Ca2+ current neuron cell bodies exposed tetraethylammonium. This could result from either a direct action on channel or opposing K+ current. Here we report voltage clamp experiments which indicate...

Serotonin exerts a long-lasting excitatory action on sensory neurons of Aplysia californica by decreasing outward K+ current. The depression current delays repolarization the potential and extends duration Ca2+ influx into presynaptic terminals, thereby contributing to facilitation transmitter release that underlies behavioral sensitization. We have extended analysis serotonin's find it acts specific serotonin-sensitive (S current), which is different from early (IA), delayed (IK),...

Guided by gut sensory cues, humans and animals prefer nutritive sugars over non-caloric sweeteners, but how the steers such preferences remains unknown. In intestine, neuropod cells synapse with vagal neurons to convey sugar stimuli brain within seconds. Here, we found that cholecystokinin (CCK)-labeled duodenal differentiate transduce luminal from sweeteners vagus nerve using sweet taste receptors sodium glucose transporters. The two stimulus types elicited distinct neural pathways: while...

Presynaptic facilitation of transmitter release contributes to behavioral sensitization and dishabituation, two simple forms learning in Aplysia. This enhancement can be simulated by the facilitatory serotonin has been shown result from types mechanisms. The first facilitating process involves broadening presynaptic action potential sensory neurons reflex is maximally effective when synapse not depressed repeated stimulation, as during sensitization. second independent changes spike duration...

Sensitization of defensive gill and siphon withdrawal reflexes in Aplysia results, part, from presynaptic facilitation transmitter release mechanoreceptor sensory neurons that innervate the skin synapse with interneurons motor neurons. Presynaptic also can be elicited by application serotonin. This is associated two phenomena, a prolongation action potential resulting decrease specific K+ current an enhancement Ca2+ transients depolarization. Previous work has shown enhances synaptic...

Significance Although conventional optogenetics utilizing microbial photosensitive channels or pumps to control activity of neurons has enabled great progress in neuroscience, reliance on delivery light by optic fibers implanted into the brain imposes certain logistical burdens and thus limits application optogenetics. To expand their utility, we fused optogenetic probes with luciferase that emits biological presence a substrate showed vitro, ex vivo, vivo could be controlled addition...

Although animal models suggest a role for blood-brain barrier dysfunction in postoperative delirium-like behavior, its delirium and recovery humans is unclear. Thus, we evaluated the of hospital length stay among older surgery patients.

The adult mammalian brain maintains a prominent stem cell niche in the subventricular zone supplying new neurons to olfactory bulb. We examined dynamics of synaptogenesis by imaging formation and elimination clusters postsynaptic marker (PSD95), genetically targeted adult-born neurons. imaged vivo periglomerular (PGNs) during two phases development, immaturity maturity. Immature PGNs showed high levels PSD95 puncta 12-72 h intervals. Mature were more stable compared with immature but still...

Birdsong, like human speech, is a series of learned vocal gestures resulting from the coordination and respiratory brainstem networks under control telencephalon. The song motor circuit includes premotor cortical analogs, known as HVC (used proper name) RA (the robust nucleus arcopallium), respectively. Previous studies showed that projects to projection neurons (PNs) topographically innervate vocal-motor networks. idea singing-related activity flows between in strictly feedforward manner...

In the sensory neurons of Aplysia, 5-HT acts through cAMP to reduce current flow two classes K+ channels, S-K + channel and a transient (Ikv). addition, increases voltage-dependent, nifedipine-sensitive Ca2+ current. this article we show that, while effect on S-K+ is mediated exclusively by cAMP, can be mimicked phorbol 12,13-dibutyrate (PDBu) as well intracellular injection cAMP. We then use specific blockers protein kinase C (PKC) cAMP-dependent A (PKA) examine roles PKC PKA in mediating...

Noxious stimulation of the tail Aplysia californica produces behavioral sensitization; it enhances several related defensive reflexes. This reflex enhancement involves heterosynaptic facilitation transmitter release from sensory neurons reflex. The is stimulated by serotonin (5-HT) and suppression a 5-HT-sensitive K+ current (the S current). Suppression broadens action potential thought to enhance prolonging entry Ca2+ in presynaptic terminals. We now report component enhanced accumulation...

Synaptic facilitation at sensory-to-motor neuron synapses in Aplysia is a mechanism contributing to simple form of learning called behavioral sensitization. Previous work has shown that mediated part by the neurotransmitter 5-HT acting through cAMP broaden presynaptic action potentials and thus increase transmitter release from sensory terminals. Other studies have indicated causes more than one mechanism, depending on whether synapse first been depressed prior stimulation. The present study...

The manipulation of genetically targeted neurons with light (optogenetics) continues to provide unprecedented avenues into studying the function mammalian brain. However, potential translation clinical arena faces a number significant hurdles, foremost among them need for insertion optical fibers brain deliver opsins expressed on neuronal membranes. In order overcome these hardware-related problems, we have developed an alternative strategy delivering which does not involve fiber implants....

Summary Paragraph/Abstract Animals innately prefer caloric sugars over non-caloric sweeteners. Such preference depends on the sugar entering intestine. 1–4 Although brain is aware of stimulus within seconds, 5–8 how gut discerns to guide choice unknown. Recently, we discovered an intestinal transducer, known as neuropod cell. 9,10 This cell synapses with vagus inform about glucose in milliseconds. 10 Here, demonstrate that cells distinguish a from sweetener using electrogenic sodium...

Chronic primary pain conditions (CPPCs) affect over 100 million Americans, predominantly women. They remain ineffectively treated, in large part because of a lack valid animal models with translational relevance. Here, we characterized CPPC mouse model that integrated clinically relevant genetic (catechol-O-methyltransferase; COMT knockdown) and environmental (stress injury) factors. Compared wild-type mice,

Zebra finches (Taeniopygia guttata) learn to produce songs in a manner reminiscent of spoken language development humans. One candidate gene implicated influencing learning is the N-methyl-D-aspartate (NMDA) subtype 2B glutamate receptor (NR2B). Consistent with this idea, NR2B levels are high song nucleus LMAN (lateral magnocellular anterior nidopallium) during juvenile vocal learning, and decreases low adults after complete becomes more stereotyped. To test for role generating plasticity,...

ABSTRACT The surface architecture of hindgut cuticle in Locusta migratoria is described. Infundibulate pores are present the midrectal pads, ileum and posterior rectum. It suggested that they lead to canals traversing cuticle. Larger occluded crater‐like on rectal pads may be glandular. colon invested with numerous spikes pointing backwards, interpad region rectum upright inwards. These probably serve direct faeces backwards from colon, impale faecal pellet during dehydration

Although animal models suggest a role for blood-brain barrier dysfunction in postoperative delirium-like behavior, its delirium and recovery humans is unclear. Thus, we evaluated the of hospital length stay among older surgery patients.