Neural Dynamics Underlying Impaired Autonomic and Conditioned Responses Following Amygdala and Orbitofrontal Lesions

A neural model is presented that explains how outcome-specific learning modulates affect, decision-making and Pavlovian conditioned approach responses. The model addresses how brain regions responsible for affective learning and habit learning interact, and answers a central question: What are the relative contributions of the amygdala and orbitofrontal cortex to emotion and behavior? In the model, the amygdala calculates outcome value while the orbitofrontal cortex influences attention and conditioned responding by assigning value information to stimuli. Model simulations replicate autonomic, electrophysiological, and behavioral data associated with three tasks commonly used to assay these phenomena: Food consumption, Pavlovian conditioning, and visual discrimination. Interactions of the basal ganglia and amygdala with sensory and orbitofrontal cortices enable the model to replicate the complex pattern of spared and impaired behavioral and emotional capacities seen following lesions of the amygdala and orbitofrontal cortex.National Science Foundation (SBE-0354378; IIS-97-20333); Office of Naval Research (N00014-01-1-0624); Defense Advanced Research Projects Agency and the Office of Naval Research (N00014-95-1-0409); National Institutes of Health (R29-DC02952

A multisensory approach to measure public space quality in the city of Bulawayo, Zimbabwe

The measurement of the quality of public space is important in spatial planning as a first step towards improved urban quality. It would seem as if city builders sometimes use their sub-jective judgements of place quality through incomprehensive sensory tools and not the users’ sensory experience and aspirations. Based on the multisensory experiences and aspirations of users as they interact with the streetscapes and public parks in Bulawayo, the purpose of this article was to develop and test the utility of a new public space quality mea-suring tool. A public space quality assess-ment was undertaken that employed a quantitative design where 400 participants were recruited through systematic sampling and data collected by means of a multisensory public space quality measurement tool. The tool and the ‘Sensory Public Space Quality Framework’ were developed to guide city planners in providing for people-centred public spaces clothed with good sensory qualities.

Gingival Taste Bud Papillae Associated with Retromolar Salivary Gland

Taste in the gustatory system allows to distinguish between safe and harmful food, and to gauge its nutritional value. Digestive enzymes in saliva begin to dissolve food into base chemicals that are detected by taste buds containing three different cell types involved in the perception of the five basic tastes. Von Ebner\u27s glands, found adjacent to the moats surrounding the circumvallate (CV) and foliate papillae, are exocrine salivary glands that secrete digestive enzymes and presumably flush material out of the papillae. Recently, we rediscovered and characterized anatomically and molecularly a chemosensory structure in the mouse oral cavity consisting of unorganized taste buds associated with ducts and a gland at the rear of the mandible, distal to the last molar and anterior to the ascending ramus. These taste buds appear to be the same ones first described by Iida in 1983, Miller in 1984, and characterized for sensory responses by Travers et al. in 1995 (Miller and Smith 1984, Travers and Norgren 1995). Here we used immunohistochemistry and RT-PCR to characterize this gingival chemosensory structure, consisting of taste buds and a minor salivary gland. Similar to the CV and foliate papillae, this novel retromolar chemosensory structure contains taste buds surrounding the orifice of ducts originating from a salivary gland (morphologically similar to the Von Ebner\u27s glands). This salivary gland is located below the mucosa of the retromolar gap, extending posteriorly in the retromolar trigone. Above the gland and ducts, taste buds are positioned on the surface of the retromolar gingival epithelium, surrounding the duct orifices. We determined that these taste buds have chemosensory features expressing many canonical taste signaling elements, including taste receptors. The composition of the secretions from the retromolar gland is unknown. The retromolar taste buds are responsible for a small portion of sensory gustatory perception (Travers and Norgren 1995). Interestingly, patients have reported taste changes following procedures involving third molar extraction, possibly due to the disruption of the retromolar tissue (Shafer, Frank et al. 1999, Akal, Kucukyavuz et al. 2004, Klasser, Utsman et al. 2008, Ridaura-Ruiz, Figueiredo et al. 2012). The retromolar taste structure possibly plays a role in taste perception and represents a potential novel pharmacological target for taste or dry mouth disorders

Dopaminergic and Non-Dopaminergic Value Systems in Conditioning and Outcome-Specific Revaluation

Animals are motivated to choose environmental options that can best satisfy current needs. To explain such choices, this paper introduces the MOTIVATOR (Matching Objects To Internal Values Triggers Option Revaluations) neural model. MOTIVATOR describes cognitiveemotional interactions between higher-order sensory cortices and an evaluative neuraxis composed of the hypothalamus, amygdala, and orbitofrontal cortex. Given a conditioned stimulus (CS), the model amygdala and lateral hypothalamus interact to calculate the expected current value of the subjective outcome that the CS predicts, constrained by the current state of deprivation or satiation. The amygdala relays the expected value information to orbitofrontal cells that receive inputs from anterior inferotemporal cells, and medial orbitofrontal cells that receive inputs from rhinal cortex. The activations of these orbitofrontal cells code the subjective values of objects. These values guide behavioral choices. The model basal ganglia detect errors in CS-specific predictions of the value and timing of rewards. Excitatory inputs from the pedunculopontine nucleus interact with timed inhibitory inputs from model striosomes in the ventral striatum to regulate dopamine burst and dip responses from cells in the substantia nigra pars compacta and ventral tegmental area. Learning in cortical and striatal regions is strongly modulated by dopamine. The model is used to address tasks that examine food-specific satiety, Pavlovian conditioning, reinforcer devaluation, and simultaneous visual discrimination. Model simulations successfully reproduce discharge dynamics of known cell types, including signals that predict saccadic reaction times and CS-dependent changes in systolic blood pressure.Defense Advanced Research Projects Agency and the Office of Naval Research (N00014-95-1-0409); National Institutes of Health (R29-DC02952, R01-DC007683); National Science Foundation (IIS-97-20333, SBE-0354378); Office of Naval Research (N00014-01-1-0624

Aerospace medicine and biology: A continuing bibliography with indexes, supplement 128, May 1974

This special bibliography lists 282 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1974

An investigation into the efficacy of a game-based learning tool to assist school children with an autistic spectrum condition to overcome sensory difficulties

This thesis discussesan investigation that has explored the efficacy of a game-based learning intervention designed to assist children with an autistic spectrum disorder overcome sensory dysfunctions. The aim of the study is to verify, through examining past research and solutions, that there is an existing need for coping strategies to address sensory dysfunction. The investigation aims to corroborate the background research by creating an intervention generated by participants on the autistic spectrum, their family and education support network that fulfils a need to minimise sensory distress. The overall purpose of the study is to show that a game based intervention catering to sensory dysfunction can be a successful application as a learning tool. The design-based research methodology used reflected the game based and participatory process which drive the intervention‟s development. The data provided by the participants was instrumental in enabling a design to be made that ostensibly met the needs of its users based on the information disclosed. Discussion takes place of the challenges that affected the investigation and how the direction of the study was steered as a result of the data acquired and adjustments that were made. The findings allowed a number of conclusions to be reached and the last chapter reflects on how the background research contributed towards the results and how the design of the development was affected as a result. The final chapter deliberates on the autistic diagnostic process, the place that sensory dysfunction takes within this procedure and how the investigation highlights the need for more consideration to be given to sensory behaviours within this process. The thesis concludes with possible answers to the research question, accompanied by an explanation of the reasons for the outcomes. Finally, contemplation is given to the findingsand how the study could benefit from further research

Differential rewarding effects of electrical stimulation of the lateral hypothalamus and parabrachial complex: Functional characterization and the relevance of opioid systems and dopamine

Background: Since the discovery of rewarding intracranial self-stimulation by Olds and Milner, extensive data have been published on the biological basis of reward. Although participation of the mesolimbic dopaminergic system is well documented, its precise role has not been fully elucidated, and some authors have proposed the involvement of other neural systems in processing specific aspects of reinforced behaviour. Aims and methods: We reviewed published data, including our own findings, on the rewarding effects induced by electrical stimulation of the lateral hypothalamus (LH) and of the external lateral parabrachial area (LPBe) – a brainstem region involved in processing the rewarding properties of natural and artificial substances – and compared its functional characteristics as observed in operant and non-operant behavioural procedures. Results: Brain circuits involved in the induction of preferences for stimuli associated with electrical stimulation of the LBPe appear to functionally and neurochemically differ from those activated by electrical stimulation of the LH. Interpretation: We discuss the possible involvement of the LPBe in processing emotional-affective aspects of the brain reward system.Desde el descubrimento de la estimulación eléctrica reforzante, por parte de Olds y Milner, se han publicado muchas investigaciones sobre las bases biológicas del refuerzo. Aunque la participación del Sistema Dopaminérgico Mesolímbico está bien documentada, su papel concreto no ha sido plenamente dilucidado y algunos investigadores han propuesto la implicación de otros sistemas neurales en el procesamiento de aspectos específicos de la conducta reforzante. Objetivo y método: Revisamoos los datos publicados -incluyendo nuestros resultados- sobre los efectos reforzantes de la estimulación eléctrica del hipotálamo lateral y del área parabraquial lateral externa (LPBe) -una región troncoencefálica involucrada en el procesamiento de las propiedades reforzantes de sustancias naturales y artificiales- y comparamos sus caracteristicas funcionales en procedimientos de aprendizaje operantes y no operantes. Resultado: Los circuitos cerebrales involucrados en la inducción de preferencias por los estímulos con que es asociada la estimulación eléctrica del LPBe parecen diferir funcional y neuroquímicamente de los activados por estimulación eléctrica del hipotálamo lateral. Interpretación: Discutimos la posible participación del LPBe en el procesamiento de los aspectos afectivo-emocionales del circuito de recompensa cerebra

The influence of scent on virtual reality experiences: The role of aroma-content congruence

We live in a multisensory world. Our experiences are constructed by the stimulation of all our senses. Nevertheless, digital interactions are mainly based on audiovisual elements, while other sensory stimuli have been less explored. Virtual reality (VR) is a sensory-enabling technology that facilitates the integration of sensory inputs to enhance multisensory digital experiences. This study analyzes how the addition of ambient scent to a VR experience affects digital pre-experiences in a service context (tourism). Results from a laboratory experiment confirmed that embodied VR devices, together with pleasant and congruent ambient scents, enhance sensory stimulation, which directly (and indirectly through ease of imagination) influence affective and behavioral reactions. These enriched multisensory experiences strengthen the link between the affective and conative images of destinations. We make recommendations for researchers and service providers with ambitions to deliver ambient scents, especially those congruent with displayed content, to enhance the sensorialization of digital VR experiences

Neuroanatomical Maps and Taste Reactivity to Sweet, Umami, and Bitter Taste in the PBN of C57BL/6J Mice

Humans can distinguish at least five different taste qualities, sour, salty, bitter, sweet, and umami (the savory taste of certain amino acids). In neuroscience research, behavioral testing is used to measure the ability of rodents (including inbred mice) to discriminate between the different taste qualities. Taste reactivity and two-bottle preference are behavioral tests that are utilized to investigate different aspects of taste. These tests involve either voluntary or forced consumption of taste stimuli, respectively. Either test can be used to infer the preference and palatability of the stimulus consumed by an animal. In order to understand the basis of taste behavior, one must understand the organization of the taste pathway. As an organism consumes a particular food or fluid, it first binds to or activates taste receptors or channels located inside taste buds found in the oral cavity. This transduction event then produces a cascade of neuronal activation via sensory nerves that innervate the taste buds –branches of three cranial nerves (VII, IX, and X). These cranial nerves then synapse centrally in the nucleus of the solitary tract (NST) where the relayed taste information is kept relatively segregated from visceral input (which arrives via cranial nerve X). From this point, the taste information is relayed to the parabrachial nucleus (PBN) in the pons, where the taste and visceral information now overlap. The PBN has not been studied as extensively as the NST in terms of taste representation, especially in regards to umami taste. A few recent studies have indicated that taste neurons in the PBN respond to sweet and synergistic umami (i.e. a combination of glutamate and a ribonucleotide) stimuli in a similar manner, providing a rationale for further study of the representation of these taste stimuli in this area. Sweet and umami taste share a common G-protein-coupled taste receptor subunit, T1R3, that responds in combination with either T1R1 to transduce umami stimuli or T1R2 to transduce sweet stimuli. Aside from sharing a common taste receptor, previous studies using pharmacological manipulations, electrophysiology, conditioned taste aversion (CTA), and discrimination studies have shown a strong functional link between sweet and umami taste in rodents. Compounds found to be sweet taste inhibitors either entirely or partially block the nerve response to the prototypical umami stimulus monosodium glutamate (MSG), as well as a synergistic mixture of MSG combined with the cyclic nucleotide inosine monophosphate (IMP). When the epithelial sodium channel blocker amiloride is combined with MSG, both rats and mice have difficulty determining the difference between this umami stimulus and sucrose. Overall, it appears that some umami stimuli appear to be perceived as sucrose-like in rodents, which differs dramatically from the human perception of umami stimuli. Although umami taste has not been studied as comprehensively in mice as it has been in rats, it is important to investigate due to the widespread use of a variety of genetic mouse models in taste research. Along with using behavioral models, one might gauge the uniqueness of sweet and umami stimuli using an anatomical technique, such as visualization of the immediate early gene c-fos in PBN neurons. In fact, previous research has indicated stimulation with different taste qualities produces distinctive c-fos patterns in the PBN. For this current research study, my first hypothesis was that since previous studies suggested the similarity between sweet and umami compounds in C57BL/6J (B6) mice; stimuli of both taste qualities would produce similar levels of preference, consumption, and levels of taste reactivity behaviors. Secondly, I hypothesized that taste stimulation with either sweet (sucrose) or umami (monopotassium glutamate; MPG, or the synergistic mixture of MPG+IMP) stimuli would produce a similar c-fos expression pattern in sweet and umami stimuli, and this would also be distinct from the c-fos expression patterns elicited by both the bitter stimulus, quinine hydrochloride (QHCl) and water. Overall, the preference tests revealed that both sucrose and umami stimuli (especially MSG+IMP) were preferred and consumed at a similarly high level in B6 mice. However, the taste reactivity test did not yield any insight into whether the sweet and umami taste stimuli were perceived as similar. However, taste reactivity to the bitter stimulus, QHCl, was easily distinguishable from the other tested taste stimuli. Using c-fos immunohistochemistry to visualize neuronal activation, I then compared staining patterns of activation evoked by: water, QHCl, sucrose, saccharin, MPG, and MPG+IMP in subdivisions of the PBN in B6 mice, as well as a few other non-taste brainstem areas (locus coeruleus and mesencephalic nucleus of the trigeminal nerve). Results showed that quinine elicited significantly less c-fos positive nuclei in the entire dorsal lateral (DL) subnucleus compared to water. A few other significant effects of the tastant stimuli were found in the rostral portion of the waist, central lateral (CL), and DL PBN subnuclei, but distinct c-fos representations were not found for each stimulus tested. To determine if tastant effects might have been subtler in terms of cell density or patterning; and therefore, could have been missed using normal cell counting methods, I decided to use a three-dimensional mapping approach to examine c-fos expression in the PBN. Results of this new mapping approach suggest its potential usage in future studies