Cat Area Research Articles

Exploring the Consistent Roles of Motor Areas Across Voluntary Movement and Locomotion.

Multiple cortical motor areas are critically involved in the voluntary control of discrete movement (e.g., reaching) and gait. Here, we outline experimental findings in nonhuman primates with clinical reports and research in humans that explain characteristic movement control mechanisms in the primary, supplementary, and presupplementary motor areas, as well as in the dorsal premotor area. We then focus on single-neuron activity recorded while monkeys performed motor sequences consisting of multiple discrete movements, and we consider how area-specific control mechanisms may contribute to the performance of complex movements. Following this, we explore the motor areas in cats that we have considered as analogs of those in primates based on similarities in their cortical surface topology, anatomic connections, microstimulation effects, and activity patterns. Emphasizing that discrete movement and gait modification entail similar control mechanisms, we argue that single-neuron activity in each area of the cat during gait modification is compatible with the function ascribed to the activity in the corresponding area in primates, recorded during the performance of discrete movements. The findings that demonstrate the premotor areas' contribution to locomotion, currently unique to the cat model, should offer highly valuable insights into the control mechanisms of locomotion in primates, including humans.

Congenital deafness reduces alpha-gamma cross-frequency coupling in the auditory cortex

Neurons within a neuronal network can be grouped by bottom-up and top-down influences using synchrony in neuronal oscillations. This creates the representation of perceptual objects from sensory features. Oscillatory activity can be differentiated into stimulus-phase-locked (evoked) and non-phase-locked (induced). The former is mainly determined by sensory input, the latter by higher-level (cortical) processing. Effects of auditory deprivation on cortical oscillations have been studied in congenitally deaf cats (CDCs) using cochlear implant (CI) stimulation. CI-induced alpha, beta, and gamma activity were compromised in the auditory cortex of CDCs. Furthermore, top-down information flow between secondary and primary auditory areas in hearing cats, conveyed by induced alpha oscillations, was lost in CDCs. Here we used the matching pursuit algorithm to assess components of such oscillatory activity in local field potentials recorded in primary field A1. Additionally to the loss of induced alpha oscillations, we also found a loss of evoked theta activity in CDCs. The loss of theta and alpha activity in CDCs can be directly related to reduced high-frequency (gamma-band) activity due to cross-frequency coupling. Here we quantified such cross-frequency coupling in adult 1) hearing-experienced, acoustically stimulated cats (aHCs), 2) hearing-experienced cats following acute pharmacological deafening and subsequent CIs, thus in electrically stimulated cats (eHCs), and 3) electrically stimulated CDCs. We found significant cross-frequency coupling in all animal groups in > 70% of auditory-responsive sites. The predominant coupling in aHCs and eHCs was between theta/alpha phase and gamma power. In CDCs such coupling was lost and replaced by alpha oscillations coupling to delta/theta phase. Thus, alpha/theta oscillations synchronize high-frequency gamma activity only in hearing-experienced cats. The absence of induced alpha and theta oscillations contributes to the loss of induced gamma power in CDCs, thereby signifying impaired local network activity.

Agriculture crop yield prediction using inertia based cat swarm optimization

Crop yield prediction is among the most important and main sources of income in the Indian economy. In this paper, the improved cat swarm optimization (ICSO) based recurrent neural network (RNN) model is proposed for crop yield prediction using time series data. The inertia weight parameter is added to position equation that is selected randomly, and a new velocity equation is produced which enhances the searching ability in the best cat area. By using inertia weight, the ICSO enhances performance of feature selection and obtains better convergence in minimum iteration. The RNN is applied to produce direct graph using sequence of data and decides current layer output by involving all other existing calculations. The performance of the model is estimated using coefficient of determination (R2), root mean square error (RMSE), mean squared error (MSE), and mean absolute error (MAE) on the yield from the years 2011 to 2021 with an annual prediction for 120 records of approximately 8 million nuts. The evaluated result shows that the proposed ICSO-RNN model delivers metrics such as R2, MAE, MSE, and RMSE values of 0.99, 0.77, 0.68, and 0.82 correspondingly, which ensures accurate yield prediction when compared with the existing methods which are hybrid reinforcement learning-random forest (RL-RF) and machine learning (ML) methods.

Agranular frontal cortical microcircuit underlying cognitive control in macaques.

The error-related negativity and an N2-component recorded over medial frontal cortex index core functions of cognitive control. While they are known to originate from agranular frontal areas, the underlying microcircuit mechanisms remain elusive. Most insights about microcircuit function have been derived from variations of the so-called canonical microcircuit model. These microcircuit architectures are based extensively on studies from granular sensory cortical areas in monkeys, cats, and rodents. However, evidence has shown striking cytoarchitectonic differences across species and differences in the functional relationships across cortical layers in agranular compared to granular sensory areas. In this minireview, we outline a tentative microcircuit model underlying cognitive control in the agranular frontal cortex of primates. The model incorporates the main GABAergic interneuron subclasses with specific laminar arrangements and target regions on pyramidal cells. We emphasize the role of layer 5 pyramidal cells in error and conflict detection. We offer several specific questions necessary for creating a specific intrinsic microcircuit model of the agranular frontal cortex.

Effects of earthworm hydrolysate in production performance, serum biochemical parameters, antioxidant capacity and intestinal function of Muscovy ducks

Earthworm has a variety of molecular biological characteristic, for example, growth promotion, antioxidant, and anti-bacteria. Thus, we decomposed earthworm by earthworm's own protease for preparing of earthworm hydrolysate. Muscovy ducks were fed with basal diet that formulated to contain 1.5% and 2.5% earthworm hydrolysate. Then, we investigated the influences of earthworm hydrolysate on growth performance in Muscovy ducks by performance terminology and measurement for poultry (NY/T 823-2020). The morphology of duodenum and number of intraepithelial lymphocytes were tested by HE staining and immunohistochemical method. Serum biochemical parameters and antioxidant capacity were also determined. High-throughput sequencing technology can sequence 16S rDNA of cecal contents from experimental Muscovy ducks. Results showed that 1.5% earthworm hydrolysate increased ADG (16-70 days old), ALB, HDL-C, T-AOC, CAT, SOD, GSH-PX, villi length, intestine thickness and surface area of villi (P < 0.05 or P < 0.01), and reduced FCR (16-70 days old), UREA, CRE, LDL-C, MDA (P < 0.05 or P < 0.01). Meanwhile, 2.5% improved ADG (16-70 days old), abdominal fat yield, breast muscle yield, heart index, spleen index, ALP, UA, T-AOC, CAT, SOD, GSH-PX, villi length, crypt depth, intestine thickness, surface area of villi, the percentage of intraepithelial lymphocytes (P < 0.05 or P < 0.01), and decreased FCR (42-70 days old and 16-70 days old), UREA, UA, MDA (P < 0.05 or P < 0.01). The sequencing results of gut flora demonstrated that earthworm hydrolysate improved variety of the gut flora in the V4 area of ducks immensely. In a word, our results provide the foundation for preliminary researching the potential principles of earthworm hydrolysate in promoting production performance, adjusting antioxidant function and intestinal functions in the Muscovy duck industry.

Dynamics and Mechanisms of Contrast-Dependent Modulation of Spatial-Frequency Tuning in the Early Visual Cortex.

The spatial-frequency (SF) tuning of neurons in the early visual cortex is adjusted for stimulus contrast. As the contrast increases, SF tuning is modulated so that the transmission of fine features is facilitated. A variety of mechanisms are involved in shaping SF tunings, but those responsible for the contrast-dependent modulations are unclear. To address this, we measured the time course of SF tunings of area 17 neurons in male cats under different contrasts with a reverse correlation. After response onset, the optimal SF continuously shifted to a higher SF over time, with a larger shift for higher contrast. At high contrast, whereas neurons with a large shift of optimal SF exhibited a large bandwidth decrease, those with a negligible shift increased the bandwidth over time. Between these two extremes, the degree of SF shift and bandwidth change continuously varied. At low contrast, bandwidth generally decreased over time. These dynamic effects enhanced the processing of high-frequency range under a high-contrast condition and allowed time-average SF tuning curves to show contrast-dependent modulation, like that of steady-state SF tuning curves reported previously. Combinations of two mechanisms, one that decreases bandwidth and shifts optimal SF, and another that increases bandwidth without shifting optimal SF, would explain the full range of SF tuning dynamics. Our results indicate that one of the essential roles of tuning dynamics of area 17 neurons, which have been observed for various visual features, is to adjust tunings depending on contrast.SIGNIFICANCE STATEMENT The spatial scales of features transmitted by cortical neurons are adjusted depending on stimulus contrast. However, the underlying mechanism is not fully understood. We measured the time course of spatial frequency tunings of cat area 17 neurons under different contrast conditions and observed a variety of dynamic effects that contributed to spatial-scale adjustment, allowing neurons to adjust their spatial frequency tuning range depending on contrast. Our results suggest that one of the essential roles of tuning dynamics of area 17 neurons, which have been observed for various visual features, is to adjust tunings depending on contrast.

Using the magnetotelluric method to study the deep structure of the Sai Gon river fault in the vicinity of Ho Chi Minh City

This paper presented the study of the two magnetotelluric profiles crossing the Saigon river fault. The first one was 13.5 km long consisting in 8 stations extending from Cu Chi district, Ho Chi Minh city to Ben Cat district, Binh Duong province, and the second was 11.7 km long including 7 stations in Nhon Trach district, Dong Nai province, Vietnam. The data were recorded in the period range 0.002‒259 s using the GEPARD-4 instrument. Because of the influence of the equatorial electrojet (EEJ) on magnetotelluric soundings in this region, only data in the period range shorter than about 1 s for the analysis were used. The resistivity data of both TE and TM modes were used for inversion using the MT2DinvMatlab software. Firstly, data were inverted down to a depth of 10 km to obtain the main electric features of the region. The results showed that on both profiles, the resistivity cross-sections showed a 3-layer geoelectric structure in which the top low resistivity layer had a thickness of about 2 km, the resistive intermediate layer was about 6‒7 km thick, and the underlying low resistivity layer. On these cross-sections, the Saigon river fault could not be observed. Then data were inverted down to 3 km to obtain more detailed information to determine the location and dip direction of the Saigon river fault. The geoelectric cross-sections of 3 km depth showed that for the Cu Chi‒Ben Cat profile, the Saigon river fault corresponded to the low resistivity region below the stations CB5 and CB6, and for the Nhon Trach profile, the river fault Saigon would be related to the low resistivity region below the stations NT3 and NT4. The obtained results confirmed the existence of the Saigon river fault, with the location and its continuous extension from the Cu Chi‒Ben Cat area, through Thu Duc city to Nhon Trach district of Đồng Nai province.

Spatial clustering of orientation preference in primary visual cortex of the large rodent agouti.

SummaryAll rodents investigated so far possess orientation-selective neurons in the primary visual cortex (V1) but – in contrast to carnivores and primates – no evidence of periodic maps with pinwheel-like structures. Theoretical studies debating whether phylogeny or universal principles determine development of pinwheels point to V1 size as a critical constraint. Thus, we set out to study maps of agouti, a big diurnal rodent with a V1 size comparable to cats'. In electrophysiology, we detected interspersed orientation and direction-selective neurons with a bias for horizontal contours, corroborated by homogeneous activation in optical imaging. Compatible with spatial clustering at short distance, nearby neurons tended to exhibit similar orientation preference. Our results argue against V1 size as a key parameter in determining the presence of periodic orientation maps. They are consistent with a phylogenetic influence on the map layout and development, potentially reflecting distinct retinal traits or interspecies differences in cortical circuitry.

Local organization of spatial frequency tuning dynamics in the cat visual areas 17 and 18.

Spatial frequency (SF) is a prominent feature to which most neurons in cat areas 17 and 18 (area 17/18) exhibit tuning selectivity. Previous studies have shown that neurons with similar SF tunings are locally clustered into SF preference domains. However, the functional organization of SF tuning remains not fully understood. Neurons in these areas show a variety of SF tuning dynamics; however, it is unknown how neurons with diverse dynamics are locally organized to form the population dynamics of the domains. The laminar organization of SF dynamics is also unknown, knowledge of which may be useful for determining how SF tuning dynamics of cat area 17/18 neurons arise in cortical circuits. To address these issues, we recorded the activities of multiple neurons in the cat area 17/18 using microelectrode arrays and characterized the time courses of the SF tunings of these neurons by a subspace reverse correlation. A wide range of SF dynamics was already present in the input layer, suggesting that intracortical mechanisms contribute to generating SF dynamics inside this layer but do not further shape it outside this layer. Local neuronal pools with similar SF tunings contained diverse SF dynamics. The average preferred SF of a pool similarly increased with response time. Moreover, the range of single-neuron preferred SFs in a pool tended to increase with time. Our results suggest that, in the presence of organized tuning diversity within an SF domain, the cortical SF organization remains stable during response time in cat area 17/18.NEW & NOTEWORTHY In cat area 17/18, we found that a local pool of neurons with similar spatial frequency (SF) tunings shows diverse but organized dynamics. Our results suggest that, in the presence of organized tuning diversity within an SF domain, the cortical SF organization remains stable over response time in these areas. Laminar analysis suggests that intracortical mechanisms contribute to generating SF dynamics inside the input layer but do not further shape it outside this layer.

Karakter dan Potensi Risiko Kerusakan Ekosistem Karst Cekungan Air Tanah Watuputih Kabupaten Rembang, Provinsi Jawa Tengah

The research area is a burgeoning karst area which is part of the Kendeng Kars area in Rembang Regency, where the karstification process continues and has a complex subsurface system. In addition to the karst area of the Watuputih Groundwater Basin (CAT) written in Presidential Decree Number 26 of 2011 point 124 is included in the CAT B classification, which is located across the regency between Rembang and Blora Regencies. The morphological changes caused by human beings and the sharing of mining activities and plans for the construction of a cement factory by PT SI and its subsidiaries such as PT SG are also investors such as PT SIR, PT RSI, PT GMM, PT BA, PT RBP, PT SAF, PT ICCI which have reached an area 493 hectares in Tegaldowo, Gunem District. These activities will directly or indirectly damage the ecosystem of caves, underground rivers and parental springs that are scattered in the Watuputih CAT area. The Bengawan Solo River, the Lusi River and the Tuyuhan River are large rivers that tipped in the Watuputih CAT area. There are 74 caves, 29 springs, 44 ponors in the Tegaldowo and Timbrangan areas, 10 caves and 3 springs in the Perhutani area. Morphological changes due to mining can affect the pattern of water distribution, where caves, springs and ponors have a very important role in controlling water supply, the degradation of the amount of water stored in the Watuputih CAT results in changes in the composition of the base flow (diffuse flow) compared to the total flow. Limestone mining will reduce the absorption function and the amount of diffuse water storage, on the contrary will increase conduit flow when it rains. If an area has criteria as karst and CAT areas then it must be a major concern in the sustainability of its ecosystem. Provide protection and stop all activities that can damage geological protected areas that have karst landscapes and water recharge, especially from small scale or massive mining activities. Provides an understanding of karst areas in the perspective of disaster risk reduction. It needs to be developed and informed to various parties across sectors and across administrations so that appropriate policies can be made as an ecological function. Keywords: Watuputih Groundwater Basin, Water Distribution, Ecosystems, Ecological Function, Protection

Hypocretin (orexin) immunoreactivity in the feline midbrain: Relevance for the generation of wakefulness

Hypocretins (Hcrt) 1 and 2 are two neuropeptides synthesized from neurons that are located in the perifornical area of the lateral hypothalamus. These neurons project diffusely throughout the central nervous system, and have been implicated in the generation and maintenance of wakefulness, as well as in critical physiological processes that occur during this behavioral state, such as motivation.The hypocretinergic projections towards the feline midbrain have not been studied before. Therefore, the aim of the present study was to analyze their relationship to the midbrain neurons, that are critically involved in the control of sleep and wakefulness. With this purpose, we examined the distribution of Hcrt1-positive fibers in the midbrain and pontomesencephalic area of the domestic cat (Felis catus), and their relationship with catecholaminergic and cholinergic neurons by means of single and double immunohistochemistry. Hcrtergic axons with distinctive varicosities and buttons were heterogeneously distributed, exhibiting different densities in distinct regions of the midbrain. High Hcrtergic fiber densities were observed in the periaqueductal gray, interpeduncular nucleus, locus coeruleus and cholinergic mesopontine regions. In addition, we studied in detail the Hcrtergic projection towards the dopaminergic nuclei of the midbrain. While very few Hcrt + fibers were observed in the substantia nigra pars compacta, the highest density of Hcrtergic fibers was found in the dopaminergic ventral periaqueductal gray area (also called A10dc area); appositions between Hcrtergic terminals and dopaminergic somata and dendrites were observed within this area. Because this dopaminergic area has been involved in the control of wakefulness, the present anatomical data provides relevant support about the role of the Hcrtergic system in the generation of this behavioral state.

A generative growth model for thalamocortical axonal branching in primary visual cortex.

Axonal morphology displays large variability and complexity, yet the canonical regularities of the cortex suggest that such wiring is based on the repeated initiation of a small set of genetically encoded rules. Extracting underlying developmental principles can hence shed light on what genetically encoded instructions must be available during cortical development. Within a generative model, we investigate growth rules for axonal branching patterns in cat area 17, originating from the lateral geniculate nucleus of the thalamus. This target area of synaptic connections is characterized by extensive ramifications and a high bouton density, characteristics thought to preserve the spatial resolution of receptive fields and to enable connections for the ocular dominance columns. We compare individual and global statistics, such as a newly introduced length-weighted asymmetry index and the global segment-length distribution, of generated and biological branching patterns as the benchmark for growth rules. We show that the proposed model surpasses the statistical accuracy of the Galton-Watson model, which is the most commonly employed model for biological growth processes. In contrast to the Galton-Watson model, our model can recreate the log-normal segment-length distribution of the experimental dataset and is considerably more accurate in recreating individual axonal morphologies. To provide a biophysical interpretation for statistical quantifications of the axonal branching patterns, the generative model is ported into the physically accurate simulation framework of Cx3D. In this 3D simulation environment we demonstrate how the proposed growth process can be formulated as an interactive process between genetic growth rules and chemical cues in the local environment.

QUALITY AND GROUNDWATER FLOW AT DEGAN, BANJARARUM, WEST PROGO

This research is a hydrogeological survey activity with the aim to determine the quality and pattern of groundwater flow in the Degan and surrounding areas, Banjararum Village, Kalibawang, West Progo District. The research method is carried out by hydrogeological surveys to collect groundwater data and groundwater quality in the form of pH, TDS and EC. The research area is included in the Dome of the Kulon Progo physiography, where this area is a non CAT area. The geomorphology of the study area in the north and west is dominated by relatively coarse landscapes forming hills, while in the central, eastern and southern parts it is a weak wavy landscape to the plains. The results showed that shallow groundwater depth of 1.2 - 10.8 m (under surface). The pattern of groundwater flow is to the east / southeast, with boundary conditions H5 and V1. Groundwater aquifers are composed of colluvium deposits and weathered - medium weathered rock. The pH value of water in the study area ranges from 6.7 -7.1; TDS is 165 - 901 ppm, while EC ranges from 187 - 1240 µS / cm. Thus, groundwater in the Degan area is neutral and tasteless.

The Influence of Groundwater Basin Existence Towards The Urban Development In Java

Groundwater is one of natural water resource that most commonly used to support the human activity. It plays an important role in shaping both physical and non-physical urban development aspect. The different availability of groundwater supply could lead into the different development rates of each area, especially in Java. The correlation between the existence of groundwater basin (CAT) and its influence to urban development could be used as base consideration to propose the development typology. Defining development typologies and what variable could distinct the developments in CAT and non-CAT area using discriminant analysis and remote sensing approach. Furthermore, there are three stages need to observe, i.e.: identify urban-rural area delineation change, defines development rates, and the last is defining discriminate variable which have significantly different means across the urban development in CAT and Non-CAT area. The observation reveals that in order to find the correlation between CAT existence and development rate, the eight-development typology has been establish. The typology is conduct regard to the development rate that categorizes in zero growth, slow growth, moderate growth, and fast growth both in CAT and Non-CAT. While, according to the result of discriminant analysis there are six variables that could distinct the urban developments in CAT and non-CAT, i.e.: proportion of dry land farm, status area, wet-land farm, built up area, agricultural household, and road density.

Comparative meta-analysis of feline leukemia virus and feline immunodeficiency virus seroprevalence correlated with GDP per capita around the globe

Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) are two prevalent transmittable diseases for domestic cats. This paper reports the frequency of these two diseases compared globally across Gross Domestic Product (GDP) at purchasing power parity per capita (PPP). Information around FeLV and FIV rates of infection in specific locations around the world was analyzed from 47 published articles. Results show that based on the data available, the statistical model indicates that the highest percentage of FeLV or FIV infected cats live in areas of lower PPP (p ≤.001) with a decreasing rate of infection of FeLV and FIV with increasing income. Two theories for this could be that the lower PPP locations in this study were also in areas of greater feral cat and cat colony populations, as well as were areas with less emphasis on animal welfare and animal control programs. Additional research should be conducted to strengthen the study size in South America and Africa before further conclusions can be drawn.

Visual cortex neurons phase-lock selectively to subsets of LFP oscillations.

It is generally thought that apart from receptive field differences, such as preferred orientation and spatial frequency selectivity, primary visual cortex neurons are functionally similar to each other. However, the genetic diversity of cortical neurons plus the existence of inputs additional to those required to explain known receptive field properties might suggest otherwise. Here we report the existence of desynchronized states in anesthetized cat area 17 lasting up to 45 min, characterized by variable narrow-band local field potential (LFP) oscillations in the range 2-100 Hz and the absence of a synchronized 1/f frequency spectrum. During these periods, spontaneously active neurons phase-locked to variable subsets of LFP oscillations. Individual neurons often ignored frequencies that others phase-locked to. We suggest that these desynchronized periods may correspond to REM sleep-like episodes occurring under anesthesia. Frequency-selective codes may be used for signaling during these periods. Hence frequency-selective combination and frequency-labeled pathways may represent a previously unsuspected dimension of cortical organization. NEW & NOTEWORTHY We investigated spontaneous neuronal firing during periods of desynchronized local field potential (LFP) activity, resembling REM sleep, in anesthetized cats. During these periods, neurons synchronized their spikes to specific phases of multiple LFP frequency components, with some neurons ignoring frequencies that others were synchronized to. Some neurons fired at phase alignments of frequency pairs, thereby acting as phase coincidence detectors. These results suggest that internal brain signaling may use frequency combination codes to generate temporally structured spike trains.

Cortical and thalamic connectivity of temporal visual cortical areas 20a and 20b of the domestic ferret (Mustela putorius furo).

The present study describes the ipsilateral and contralateral corticocortical and corticothalamic connectivity of the temporal visual areas 20a and 20b in the ferret using standard anatomical tract-tracing methods. The two temporal visual areas are strongly interconnected, but area 20a is primarily connected to the occipital visual areas, whereas area 20b maintains more widespread connections with the occipital, parietal and suprasylvian visual areas and the secondary auditory cortex. The callosal connectivity, although homotopic, consists mainly of very weak anterograde labeling which was more widespread in area 20a than area 20b. Although areas 20a and 20b are well connected with the visual dorsal thalamus, the injection into area 20a resulted in more anterograde label, whereas more retrograde label was observed in the visual thalamus following the injection into area 20b. Most interestingly, comparisons to previous connectional studies of cat areas 20a and 20b reveal a common pattern of connectivity of the temporal visual cortex in carnivores, where the posterior parietal cortex and the central temporal region (PMLS) provide network points required for dorsal and ventral stream interaction enroute to integration in the prefrontal cortex. This pattern of network connectivity is not dissimilar to that observed in primates, which highlights the ferret as a useful animal model to understand visual sensory integration between the dorsal and ventral streams. The data generated will also contribute to a connectomics database, to facilitate cross species analysis of brain connectomes and wiring principles of the brain.

Cell-Type-Specific Thalamocortical Inputs Constrain Direction Map Formation in Visual Cortex

Finding the relationship between individual cognitive functions and cell-type-specific neuronal circuits is acentral topic in neuroscience. In cats, the lateral geniculate nucleus (LGN) contains several cell types carrying spatially and temporally precise visual information. Whereas LGN cell types lack selectivity for motion direction, neurons in the primary visual cortex (area 17) exhibit sharp direction selectivity. Whether and how such de novo formation of direction selectivity depends on LGN cell types remains unknown. Here, we addressed this question using invivo two-photon calcium imaging in cat area 17, which consists of two compartments receiving different combinations of inputs from the LGN cell types. The direction map in area 17 showed unique fragmented organization and was present only in small and distributed cortical domains. Moreover, direction-selective domains preferentially localized in specific compartments receiving Y and W inputs carrying low spatial frequency visual information, indicating that cell-type-specific thalamocortical projections constrain the formation of direction selectivity.

The unfinished journey with modafinil and discovery of a novel population of modafinil-immunoreactive neurons

Modafinil, a wake-promoting compound now used worldwide in sleep medicine, was initially regarded as a sedative compound because mice were so quiet with respect to locomotion after receiving it that this behavioral state was qualified as sedation. In the early 1980's when modafinil was first assessed by polysomnography in a cat in our laboratory, surprisingly, the cat spent the whole night awake without even one minute of sleep! This initial observation resulted subsequently in a series of basic and clinical studies in order to define the pharmacological profile of modafinil and its mode of action and, notably, to identify the brain targets by which modafinil acts to promote wakefulness. These studies were undertaken using pharmacologic approach coupled with the Cerveau isolé (brain transection) preparation, c-fos labelling and knockout mouse models. It was also in this context that we have developed a purified polyclonal antibody against modafinil. We expected that using immunohistochemistry with this antibody would allow us to localize the brain distribution of modafinil dosing. Surprisingly, we found discrete modafinil immunoreactive neuronal populations in several brain areas of modafinil-naive cats, rodents and humans. The most numerous and intensely labeled modafinil-immunoreactive neurons characterized by granular staining were found in the basal forebrain. They shared the regional location with cholinergic and aspartate-containing neurons but did not colocalize with them. In summary, we here present a newly identified neuronal population located in the basal forebrain that has never previously been published and suggests that these modafinil-immunoreactive neurons might be involved in forebrain functions such as sleep-wake control and cognition. This paper briefly reviews our journey with modafinil research and presents new unpublished experimental data.

The Common and Distinct Orientation Adaptation Effect at Pinwheel Centers in Areas 21a and 17 of Cats

Cortices are non-uniform in their capacity for adaptive changes. In cat area 17, pinwheel centers of the orientation map demonstrated much greater selectivity shifts after the orientation adaptation than the iso-orientation domains (Dragoi et al., 2001a). However, whether this heterogeneity exists in other visual cortical regions remains unclear. Similar to area 17, area 21a neurons in cats are well known to be functionally clustered according to their orientation preference in iso-orientation domains that converge at pinwheel centers but with a higher pinwheel density (Huang et al., 2006). In this study, we simultaneously measured the adaptation effects on the orientation maps in area 17 and area 21a of anesthetized cats by intrinsic signal optical imaging. We found that in area 21a, the adaptation-induced selectivity shifts were significantly larger at pinwheel centers, similar to the findings in area 17. However, at either pinwheel centers or iso-orientation domains, the selectivity shifts in area 21a were all consistently greater than those in area 17, even though the heterogeneity in the orientation distribution was similar in the two areas. More importantly, in our short-term adaptation protocol, orientation adaptation in area 17 resulted in mostly repulsive shifts at the pinwheel center region, while in area 21a, it induced both repulsive and attractive effects. These results suggest that both common and distinct strategies exist for orientation adaptation across cortices and sub-regions.