Stages of nonsymbolic number processing in occipitoparietal cortex disentangled by fMRI adaptation

The neurobiological mechanisms of nonsymbolic number processing in humans are still unclear. Computational modeling proposed three successive stages: first, the spatial location of objects is stored in an object location map; second, this information is transformed into a numerical summation code; third, this summation code is transformed to a number-selective code. Here, we used fMRI-adaptation to identify these three stages and their relative anatomical location. By presenting the same number of dots on the same locations in the visual field, we adapted neurons of human volunteers. Occasionally, deviants with the same number of dots at different locations or different numbers of dots at the same location were shown. By orthogonal number and location factors in the deviants, we were able to calculate three independent contrasts, each sensitive to one of the stages. We found an occipitoparietal gradient for nonsymbolic number processing: the activation of the object location map was found in the inferior occipital gyrus. The summation coding map exhibited a nonlinear pattern of activation, with first increasing and then decreasing activation, and most activity in the middle occipital gyrus. Finally, the number-selective code became more pronounced in the superior parietal lobe. In summary, we disentangled the three stages of nonsymbolic number processing predicted by computational modeling and demonstrated that they constitute a pathway along the occipitoparietal processing stream

Number Processing Pathways in Human Parietal Cortex

Numerous studies have identified the intraparietal sulcus (IPS) as an area critically involved in numerical processing. IPS neurons in macaques are tuned to a preferred numerosity, hence neurally coding numerosity in a number-selective way. Neuroimaging studies in humans have demonstrated number-selective processing in the anterior parts of the IPS. Nevertheless, the processes that convert visual input into a number-selective neural code remain unknown. Computational studies have suggested that a neural coding stage that is sensitive, but not selective to number, precedes number-selective coding when processing nonsymbolic quantities but not when processing symbolic quantities. In Experiment 1, we used functional magnetic resonance imaging to localize number-sensitive areas in the human brain by searching for areas exhibiting increasing activation with increasing number, carefully controlling for nonnumerical parameters. An area in posterior superior parietal cortex was identified as a substrate for the intermediate number-sensitive steps required for processing nonsymbolic quantities. In Experiment 2, the interpretation of Experiment 1 was confirmed with a connectivity analysis showing that a shared number-selective representation in IPS is reached through different pathways for symbolic versus nonsymbolic quantities. The preferred pathway for processing nonsymbolic quantities included the number-sensitive area in superior parietal cortex, whereas the pathway for processing symbolic quantities did not

Development of surgical site infections despite perioperative antimicrobial therapy in two dogs

Surgical site infections (SSI) are common complications with a prevalence of 0.8 to 18%. Many risk factors, such as patient, environmental and treatment factors can contribute to the development of SSI. Two dogs that developed a SSI after forelimb amputation are discussed. The first dog was presented with an open comminuted intra-articular fracture of the right elbow. The second dog was diagnosed with a soft-tissue sarcoma at the right elbow. Perioperative cefazolin was administered in both patients. Only in the first patient, antimicrobial therapy was continued in the postoperative period. Both dogs developed an SSI within four to five days postoperatively. Yet, prophylactic antimicrobials can help to prevent SSI, provided that the correct antimicrobial is used at the correct dose, at the right time and given IV. Factors, such as hypothermia, violating the Halsted's principles and the number of people present in the theater may increase the risk of SSI. Besides the meticulous use of antimicrobials, perioperative management is thus also important in SSI prevention

Anesthesie bij de obese hond en kat = Anesthesia of obese dogs and cats

Obesity is a major issue in veterinary medicine. It is not only an accumulation of fat, but obesity also has important cardiovascular and respiratory implications. Therefore, it can strongly influence the anesthesia in obese patients. In addition, obesity can have an underlying cause or may lead to related conditions, which can complicate the anesthesia. Finally, obesity leads to changes in the pharmacodynamics and kinetics of certain drugs, such as anesthetics. These changes require dose adjustments depending on the anesthetic. Unfortunately, the available information is very limited in veterinary medicine and is mainly obtained by extrapolation from human medicine. In this article, an overview is provided of the pathophysiological and pharmacological changes in obese animals, which are important during anesthesia

Neurological signs and imaging findings in three cats with multiple articular process hypertrophy = Neurologische symptomen en resultaten van medische beeldvorming bijdrie katten met hypertrofie van multipele articulaire processen

An eight-year-old British Shorthair (case 1), an eleven-year-old British Shorthair (case 2) and a six-year-old European Shorthair cat (case 3) showed signs of chronic T3–L3 myelopathy. Computed tomography of the thoracolumbar and lumbosacral region was performed in all three cases and magnetic resonance imaging was only performed in case 2. Cross sectional imaging revealed an enlargement of the articular process joints from T2 to T5 in case 1, from T11 to T13 in case 2 and from T10 to T13 in case 3 causing spinal cord compression. Based on the severity of the spinal cord compression, surgical decompression by hemilaminectomy was performed in case 1. In cases 2 and 3, conservative treatment was instituted, although this condition could have been an incidental finding in these two cases. To the authors’ knowledge, this is the first report describing the neurological signs, imaging findings and short-term outcome in cats with multiple thoracolumbar articular process hypertrophy

Repetitive transcranial magnetic stimulation in drug‐resistant idiopathic epilepsy of dogs : a noninvasive neurostimulation technique

Background Although repetitive transcranial magnetic stimulation (rTMS) has been assessed in epileptic humans, clinical trials in epileptic dogs can provide additional insight. Objectives Evaluate the potential antiepileptic effect of rTMS in dogs. Animals Twelve client-owned dogs with drug-resistant idiopathic epilepsy (IE). Methods Single-blinded randomized sham-controlled clinical trial (dogs allocated to active or sham rTMS) (I) and open-labeled uncontrolled clinical trial (dogs received active rTMS after sham rTMS) (II). Monthly seizure frequency (MSF), monthly seizure day frequency (MSDF), and number of cluster seizures (CS) were evaluated for a 3-month pre-TMS and post-rTMS period and safety was assessed. The lasting effect period of rTMS was assessed in each dog treated by active stimulation using the MSF ratio (proportion of post-TMS to pre-rTMS MSF) and treatment was considered effective if the ratio was No adverse effects were reported. In trial I, MSF and MSDF decreased significantly (P= .04) in the active group (n = 7). In the sham group (n = 5), no significant changes were found (P= .84 and .29, respectively). Cluster seizures did not change significantly in either group. No significant differences were detected between the groups. In trial II, previously sham-treated dogs (n = 5) received active rTMS and significant decreases in MSF and MSDF were noted (P= .03 and .008, respectively). The overall effect of rTMS lasted for 4 months; thereafter, the MSF ratio was >1. Conclusions and Clinical Importance Repetitive transcranial magnetic stimulation may be a safe adjunctive treatment option for dogs with drug-resistant IE, but large-scale studies are needed to establish firm conclusions

Cardiopulmonary resuscitation and the RECOVER guidelines at the Faculty of Veterinary Medicine, Ghent University

The implementation of the RECOVER guidelines at the Small Animal Department, Faculty of Veterinary Medicine of the Ghent University was assessed by performing both a cross-sectional research and a study on the impact of training. During a six-month prospective cross-sectional study, 39 patients, which underwent cardiopulmonary resuscitation (CPR), were recorded. This corresponds with an incidence of 1.8% of all hospitalized patients that underwent CPR during the same period. Of these cases, 32 were included in the statistics. Return of spontaneous circulation (ROSC) was obtained in eleven patients (34.3%), but only one dog (3.1%) survived to discharge. In this study, an association between hemolymphatic disease as concomitant disease and not obtaining ROSC was shown. Subsequently, four cardiopulmonary resuscitation (CPR) training sessions were organized. The confidence of the participants was evaluated before and after these training sessions and showed a significant increase after the training session. With increased training of all personnel and students involved in CPR efforts, the aim of this study was to increase positive outcomes and to achieve a more standardized CPR protocol

Priming reveals differential coding of symbolic and non-symbolic quantities

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