In active sensation, sensory information is acquired via movements of organs; rats move their whiskers repetitively to scan the environment, thus detecting, localizing, and identifying objects. Sensory information, in turn, affects future motor movements. How this motor-sensory-motor functional loop implemented across anatomical loops whisker system not yet known. While inducing artificial whisking anesthetized rats, we recorded activity individual neurons from three thalamic nuclei system,...

The vibrissal system of the rat is an example active tactile sensing, and has recently been used as a prototype in construction touch-oriented robots. Active exploration touch are enabled controlled by musculature mystacial pad. So far, knowledge about motor control extracted from what known systems other species, mainly mice hamsters, since detailed description pad was lacking. In present work, revealed slicing four different planes, staining slices for cytochrome oxidase, tracking spatial...

How does processing of information change the internal representations used in subsequent stages sensory pathways? To approach this question, we studied whisker movements lemniscal and paralemniscal pathways rat vibrissal system. We recently suggested that these two encode movement frequency different ways. proposed thalamocortical circuits, functioning as phase-locked loops (PLLs), translate temporally coded into a rate code. Here focus on major trigeminal nuclei brain stem, nucleus...

Part of the information obtained by rodent whiskers is carried frequency their movement. In thalamus anesthetized rats, whisker represented two different coding schemes: amplitude and spike count (i.e., response amplitudes counts decrease as a function frequency) in lemniscal latency (latencies increase paralemniscal (see accompanying paper). Here we investigated neuronal representations primary somatosensory (“barrel”) cortex rat, which receives its input from both thalamic nuclei. Single...

Summary Facial vibrissae, or whiskers, are found in nearly all extant mammal species and likely to have been present early mammalian ancestors. A sub-set of modern mammals, including many rodents, move their vibrissae back-and-forth at high speed whilst exploring a behaviour known as "whisking". It is not whether the mammals moved this way. The gray short-tailed opossum, Monodelphis domestica, considered useful from perspective tracing evolution mammals. Interestingly, these marsupials...

The temporally encoded information obtained by vibrissal touch could be decoded "passively," involving only input-driven elements, or "actively," utilizing intrinsically driven oscillators. A previous study suggested that the trigeminal somatosensory system of rats does not obey bottom-up order activation predicted passive decoding. Thus, we have tested whether this obeys predictions active We studied cortical single units in cortices anesthetized and guinea pigs found about a quarter them...

All mammals (apart from apes and humans) have whiskers that make use of a similar muscle arrangement. Whisker specialists, such as rats mice, tend to be nocturnal arboreal, relying on their whisker sense touch guide exploration around tree canopies at night. As such, arboreal rodents many are organised into grid-like pattern, moved using complex array muscles. Indeed, most specialised longer arranged in dense, regular grid, compared with terrestrial, diurnal mammals. The guinea pig diverged...

The spatial organization of the anatomical structures along trigeminal afferent pathway rat conserves topographical order receptor sheath: brainstem barrelettes, thalamic barreloids, and cortical barrels all reflect arrangement whiskers across mystacial pad. Although both amount innervation in pad size were shown previously to exhibit increasing gradients toward ventral caudal whiskers, whether similar existed thalamus was not known. Here, authors investigated barreloids posteromedial...

Brains adapt to new situations by retuning their neurons. The most common form of neuronal adaptation, typically observed with repetitive stimulations passive sensory organs, is depression (responses gradually decrease until stabilized). We studied cortical adaptation when stimuli are acquired active movements the organ. In anesthetized rats, artificial whisking was induced at 5 Hz, and activity individual neurons in layers 2–5 recorded during air (Whisking condition) against an object...

The involvement of acetylcholine (ACh) in the induction neuronal sensory plasticity is well documented. Recently we demonstrated somatosensory cortex anesthetized rat that ACh also involved expression plasticity. Pairing stimulation principal whisker at a fixed temporal frequency with iontophoresis induced potentiations response required re-application to be expressed. Here fully characterize this phenomenon and extend it adjacent whiskers. We show these ACh-dependent are cumulative...

Abstract Histochemical examination of the dorsorostral quadrant rat snout revealed superficial and deep muscles that are involved in whisking, sniffing, airflow control. The part M. nasolabialis profundus acts as an intrinsic (follicular) muscle to facilitate protraction translation vibrissae is described. An intraturbinate selected rostral‐most nasal can influence major routs inspiratory rhinarial touch through their control nostril configuration, atrioturbinate rhinarium position, were...

In whisking rodents, object location is encoded at the receptor level by a combination of motor and sensory related signals. Recoding signals can result in various forms internal representations. Here, we examined coding schemes occurring first forebrain that receives inputs necessary for generating such representations--the thalamocortical network. Single units were recorded 8 thalamic cortical stations artificially anesthetized rats. Neuronal representations generated across these...

Coordinated action of facial muscles during whisking, sniffing, and touching objects is an important component active sensing in rodents. Accumulating evidence suggests that the anatomical schemes underlie are similar across majority whisking Intriguingly, however, muscle architecture mystacial pad mouse was reported to be different, possessing only one extrinsic vibrissa protracting (M. nasalis) rostral part snout. In this study, organization move nose vibrissae mice re-examined compared...

In a number of mammals muscle dilator nasi (naris) has been described as that reduces nasal airflow resistance by dilating the nostrils. Here we show in rats tendon this inserts into aponeurosis above cartilage. Electrical stimulation raises nose and deflects it laterally towards side stimulation, but does not change size nares. alert head-restrained rats, electromyographic recordings reveal is active during motion rather than nares dilation. Together these results suggest an alternative...

Abstract Anatomical and functional integrity of the rat mystacial pad (MP) is dependent on intrinsic organization its extracellular matrix. By using collagen autofluorescence, in MP, we revealed a collagenous skeleton that interconnects whisker follicles, corium, deep layers. We suggest this supports MP tissues, mediates force transmission from muscles to whiskers, facilitates retraction after protraction, limits extensibility. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.

ABSTRACT The rhinarium is the rostral‐most area of snout that surrounds nostrils, and hairless in most mammals. In rodents, it participates coordinated behaviors, active tactile sensing, olfactory sensing. rats, firmly connected to nasal cartilages, its motility determined by movements rostral end cartilaginous skeleton (NCS). Here, we demonstrate nature different regions form nasofacial muscles deform these during NCS. These muscles, together with dorsal cartilage described here, function...

Smell and touch convey most of the information that nocturnal rodents collect in their natural environments, each via its own complex network muscles, receptors neurons. Being active senses, a critical factor determining integration sensations relates to degree coordination. While it has been known for nearly 50 years sniffing whisking can be coordinated, dynamics such coordination dependency on behavioral environmental conditions are not yet understood. Here we introduce novel non-invasive...

The arrangements of vibrissae in guinea pigs and golden hamsters were previously reported to be different from those mice rats. Whereas the mystacial pads rats include four straddlers five rows vibrissae, described possess six irregularly aligned no straddlers, seven vibrissal also straddlers. We found that all these species similar within pad. To demonstrate this similarity, we developed a new method sinus hair visualization flattened cleared preparations Intrinsic muscles pad revealed...

Abstract Rats' whisking motion and objects' palpation produce tactile signals sensed by mechanoreceptors at the vibrissal follicles. Rats adjust their patterns to target information type, flow, resolution, adapting behavioral needs changing environment. This coordination requires control over activity of mystacial pad's intrinsic extrinsic muscles. Studies have relied on muscle recording stimulation techniques describe roles individual However, these methods lack resolution isolate small...

The ventral posteromedial thalamic nucleus (VPM) of the rat contains at least two major vibrissa-representing compartments: dorsomedial (VPMdm), which belongs to lemniscal afferent pathway, and ventrolateral (VPMvl), extralemniscal pathway. Although input-output projections functional characteristics that distinguish these compartments were recently clarified, a comprehensive structural analysis border between them was lacking. This paper addresses relationships VPMdm VPMvl. We found size...