Biomedical subjects

B J Everitt

Publications and source records attributed to B J Everitt.

At least 91 records · Page 5Linked to original sources

PubMed1997

Contrasting effects of systemic and intracerebral infusions of the 5-HT1A receptor agonist 8-OH-DPAT on spatial short-term working memory in rats.

The present study compared the effects of systemic 8-OH-DPAT (0.05, 0.1 and 1.0 mg/kg) with intra-raphe and intra-hippocampal infusions of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) (10, 30 100 ng) on delayed non-matching-to-position (DNMP) performance in rats. The highest dose of 8-OH-DPAT administered systemically impaired DNMP performance in a delay-independent manner, increased premature responding and increased response bias. Infusions of 8-OH-DPAT (100 ng) into the median raphe nucleus improved performance accuracy, independent of delay whilst having no effect on any other response measure. Infusions of 8-OH-DPAT into the dorsal raphe nucleus had no effect on performance at any dose tested. Infusions of 8-OH-DPAT into the dorsal hippocampus produced a small impairment in performance which was also independent of delay. However, this decrement in performance accuracy was not accompanied by any changes in other response measures. These findings demonstrate a dissociation between the effects of stimulation of pre- and post-synaptic 5-HT1A receptors on performance of a DNMP task although the changes in performance cannot be accounted for by changes in mnemonic function.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1997

Doubly dissociable effects of median- and dorsal-raphé lesions on the performance of the five-choice serial reaction time test of attention in rats.

Six experiments examined the effects of selective median (MRN)- and dorsal (DRN)-raphé nucleus lesions on the performance of the five-choice serial reaction time task. In this test rats are required to localize brief visual stimuli presented randomly in one of five locations in approximately 30 min sessions of 100 trials. Both accuracy and latency to respond are measured, as well as the incidence of premature and perseverative responding. Selective 5-HT lesions were induced by intra-raphé infusions of 5,7-dihydroxytryptamine following pretreatment with both a noradrenergic and a dopaminergic re-uptake inhibitor. Analysis of tissue monoamine content demonstrated that the MRN lesion profoundly depleted hippocampal 5-HT (by about 90%) without affecting noradrenaline and dopamine, whereas the DRN lesion primarily depleted (by about 80%) nucleus accumbens and caudate-putamen 5-HT. Rats with 5-HT lesions of the MRN performed the task with a similar degree of accuracy to that exhibited by sham-operated controls. Although the MRN lesion did not affect the latency to respond correctly to the visual targets the lesioned animals collected the food reward significantly faster than the controls. A transient increase in the number of premature responses also resulted from this lesion. In contrast the DRN lesion produced a transient but significant increase in the accuracy of performance, and increased both the speed and the probability of responding. The similarity of the effects following global forebrain 5-HT depletion and the selective DRN lesion suggests that the 5-HT projections of the DRN rather than the MRN may play an important role in impulsive behaviour following 5-HT depletion.

5,7-Dihydroxytryptamine↗

PubMed1997

Cognitive enhancers in theory and practice: studies of the cholinergic hypothesis of cognitive deficits in Alzheimer's disease.

The current status of the cholinergic hypothesis of cognitive dysfunction in Alzheimer's disease is reviewed in the context of recent attempts to alleviate specific cognitive impairments produced in rats by excitotoxic lesions of basal forebrain neurons by treatment with cholinergic agents. AMPA-induced lesions of the nucleus basalis region in rats produce profound and relatively specific reductions in neocortical markers of cholinergic function but fail to affect performance in many tests of memory and learning in rats. However, such lesions produce specific deficits in responding accurately in a test of visual attentional performance, which are reversed dose-dependently by treatment with systemic physostigmine or nicotine. Analogous improvements have been reported in a clinical trial of the anticholinesterase tacrine in patients with Alzheimer's disease. By contrast, AMPA-induced lesions of the medial septum produce profound reductions in hippocampal acetylcholine and accompanying delay-dependent deficits in a delayed non-matching-to-position procedure which measures spatial working memory in rats. This impairment is shown to be reversed to some extent by treatment with low doses of physostigmine. The results are discussed in terms of the multivariate nature of the neurochemical pathology of Alzheimer's disease and attendant limitations in the use of the cholinergic strategy. The cognitive costs, as well as benefits, of cognitive enhancers are discussed, as well as the need to broaden our therapeutic approach to other neurotransmitter systems and other neurodegenerative disorders.

Alzheimer Disease↗

PubMed1997

Contrasting effects of excitotoxic lesions of the prefrontal cortex on the behavioural response to D-amphetamine and presynaptic and postsynaptic measures of striatal dopamine function in monkeys.

The effects of excitotoxic lesions of the prefrontal cortex on behavioural, neurochemical and molecular indices of dopamine function in the caudate nucleus were studied in the marmoset. The lesion, which encompassed both the lateral and orbital regions of prefrontal cortex, made the animals more sensitive to the performance disrupting effects of the dopamine releasing drug, D-amphetamine, in a variation of the object retrieval task. Specifically, following drug administration, the lesioned marmosets were less able to gain access to food reward in the minimum number of responses. Analysis of the nature of the errors suggested that the deficit was not due to inhibition of a prepotent response as the lesioned monkeys were just as likely to make a detour reach to the unopened side of the box as a direct "line-of-sight" reach into the unopened front of the box. Rather, the data indicated a general disorganization of behaviour. The enhanced behavioural responsiveness to manipulations increasing presynaptic dopamine function was accompanied by neurochemical changes indicating a reduced responsiveness, as revealed by in vivo microdialysis. Thus, in lesioned animals, whilst there were no effects on baseline levels of extracellular dopamine in dorsolateral caudate, evoked release, both to systemic D-amphetamine and to a local depolarizing pulse of potassium ions, was attenuated. These opposite effects of the prefrontal cortex lesion on behavioural and neurochemical indices of striatal dopamine function occurred in the absence of any changes in striatal dopamine receptors of the D1 and D2 subtype, as determined both by radioligand binding assays and measurements of messenger RNA using in situ hydridization techniques. These data provide further insight into the interactions between prefrontal cortex and striatal dopamine function in the non-human primate. In particular, when taken in the light of our previous studies they indicate that following prefrontal manipulations, concurrence between behavioural and neurochemical indices of striatal dopamine function depends, critically, on the behavioural task. These findings are discussed with respect to the growing body of evidence implicating abnormalities in frontostriatal neurotransmission in complex disorders such as schizophrenia.

Analysis of Variance↗

PubMed1997

Dissociable effects of cingulate and medial frontal cortex lesions on stimulus-reward learning using a novel Pavlovian autoshaping procedure for the rat: implications for the neurobiology of emotion.

The effects of quinolinic acid-induced lesions of the anterior cingulate, posterior cingulate, and medial frontal cortices on stimulus-reward learning were investigated with a novel Pavlovian autoshaping procedure in an apparatus allowing the automated presentation of computer-graphic stimuli to rats (T. J. Bussey, J. L. Muir, & T. W. Robbins, 1994). White vertical rectangles were presented on the left or the right of a computer screen. One of these conditioned stimuli (the CS+) was always followed by the presentation of a sucrose pellet; the other, the CS-, was never followed by reward. With training, rats came to approach the CS+ more often than the CS-. Anterior cingulate cortex-lesioned rats failed to demonstrate normal discriminated approach, making significantly more approaches to the CS- than did sham-operated controls. Medial frontal cortex-lesioned rats acquired the task normally but had longer overall approach latencies. Posterior cingulate cortex lesions did not affect acquisition.

Animals↗

PubMed1997

Triple dissociation of anterior cingulate, posterior cingulate, and medial frontal cortices on visual discrimination tasks using a touchscreen testing procedure for the rat.

Four experiments examined effects of quinolinic acid-induced lesions of the anterior cingulate, posterior cingulate, and medial frontal cortices on tests of visual discrimination learning, using a new "touchscreen" testing method for rats. Anterior cingulate cortex lesions impaired acquisition of an 8-pair concurrent discrimination task, whereas posterior cingulate cortex lesions facilitated learning but selectively impaired the late stages of acquisition of a visuospatial conditional discrimination. Medial frontal cortex lesions selectively impaired reversal learning when stimuli were difficult to discriminate; lesions of anterior and posterior cingulate cortex had no effect. These results suggest roles for the anterior cingulate, posterior cingulate, and medial frontal cortex in stimulus-reward learning, stimulus-response learning or response generation, and attention during learning, respectively.

Animals↗

PubMed1997

Central cholinergic systems and cognition.

The organization and possible functions of basal forebrain and pontine cholinergic systems are reviewed. Whereas the basal forebrain cholinergic neuronal projections likely subserve a common electrophysiological function, e.g. to boost signal-to-noise ratios in cortical target areas, this function has different effects on psychological processes dependent upon the neural network operations within these various cortical domains. Evidence is presented that (a) the nucleus basalis-neocortical cholinergic system contributes greatly to visual attentional function, but not to mnemonic processes per se; (b) the septohippocampal projection is involved in the modulation of short-term spatial (working) memory processes, perhaps by prolonging the neural representation of external stimuli within the hippocampus; and (c) the diagonal band-cingulate cortex cholinergic projection impacts on the ability to utilize response rules through conditional discrimination. We also suggest that nucleus basalis-amygdala cholinergic projections have a role in the retention of affective conditioning while brainstem cholinergic projections to the thalamus and midbrain dopamine neurons affect basic arousal processes (e.g. sleep-wake cycle) and behavioral activation, respectively. The possibilities and limitations of therapeutic interventions with procholinergic drugs in patients with Alzheimer's disease and other neurodegenerative disorders in which basal forebrain cholinergic neurons degenerate are also discussed.

Animals↗

PubMed1996

The biological, social and clinical bases of drug addiction: commentary and debate.

This article summarizes the main discussions at a meeting on the biological, social and clinical bases of drug addiction focused on contemporary topics in drug dependence. Four main domains are surveyed, reflecting the structure of the meeting: psychological and pharmacological factors; neurobiological substrates; risk factors (including a consideration of vulnerability from an environmental and genetic perspective); and clinical treatment. Among the topics discussed were tolerance, sensitization, withdrawal, craving and relapse; mechanisms of reinforcing actions of drugs at the behavioural, cognitive and neural levels; the role of subjective factors in drug dependence; approaches to the behavioural and molecular genetics of drug dependence; the use of functional neuroimaging; pharmaceutical and psychosocial strategies for treatment; epidemiological and sociological aspects of drug dependence. The survey takes into account the considerable disagreements and controversies arising from the discussions, but also reaches a degree of consensus in certain areas.

Brain↗

PubMed1996

Dissociable effects of AMPA-induced lesions of the vertical limb diagonal band of Broca on performance of the 5-choice serial reaction time task and on acquisition of a conditional visual discrimination.

The aim of the present study was to investigate the role of the cholinergic innervation of the cingulate cortex in visual attentional function and acquisition of a visual conditional discrimination task. Following AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) lesions of the vertical limb diagonal band of Broca (VDB) which provides the main cholinergic projection to cingulate cortex, animals were not significantly impaired on the 5-choice serial reaction time task. This task, which provides a continuous performance test of visual attention, has previously been shown to be sensitive to AMPA lesions of the nucleus basalis magnocellularis (nbM). In contrast to the results obtained for visual attentional function, lesions of the VDB did significantly affect the acquisition of a visual conditional discrimination. While showing a significant facilitation in the early learning stage of acquiring this task animals with lesions of the VDB were significantly impaired during the late stages of learning this task. This late learning deficit was not the result of the animals being unable to learn the task due to the presence of the lesion throughout task acquisition as the results of a second experiment revealed that when animals were pre-trained to 70% accuracy on the task and then lesioned, the impairment in late learning was still apparent. In light of the results presented in the accompanying paper (Bussey et al., Behav. Brain Res., 1996), these results suggest that the early learning effects may be due to cholinergic denervation of the anterior cingulate cortex while the late learning effects may be due to denervation of the posterior cingulate cortex. Taken together with previous work indicating a role for the nbM cholinergic system in visual attentional function, these results suggest a role for the cholinergic innervation of the cingulate cortex in conditional learning but not for continuous attentional performance.

Animals↗

PubMed1996

Dissociable effects of anterior and posterior cingulate cortex lesions on the acquisition of a conditional visual discrimination: facilitation of early learning vs. impairment of late learning.

Two experiments investigated the effects of quinolinic acid induced lesions of the anterior and posterior cingulate cortices on the acquisition and performance of a conditional visual discrimination (CVD) task, in which rats were required to learn a rule of the type: "If lights are flashing FAST, press the right lever; if SLOW press left". In Experiment 1, animals with lesions of the anterior cingulate cortex (ANT group) demonstrated a significant enhancement in learning during the early stages of task acquisition. Conversely, animals with lesions of the posterior cingulate cortex (POS group) were impaired in learning during the later stages of acquisition. There were no significant differences between the ANT and POS groups on the performance of the task when either variable inter-trial intervals or reduced stimulus durations were imposed. In Experiment 2, the specificity of the lesion effects for processes operative during the early and late stages of learning was tested. Animals were trained to a criterion of 70% correct choices on two consecutive sessions prior to lesioning, and subsequently allowed to continue to acquire the task to the mean asymptotic performance level of 85% correct choices on two consecutive sessions. Animals of the POS group were impaired in learning during this later stage of task acquisition, thus replicating the pattern of results obtained in Experiment 1. The animals in Experiment 2 were then tested following a 30-day retention interval and during extinction (removal of sucrose from the magazine). The extinction test revealed an impairment in the ability of animals in the ANT group to omit lever responses in the absence of reinforcement. These results indicate that the anterior and posterior cingulate cortices are functionally dissociable, and suggest that they may form part of complementary, but competing, learning and memory systems.

Animals↗

PubMed1996

Neurobehavioural mechanisms of reward and motivation.

The analysis of the behavioural and neural mechanisms of reinforcement and motivation has benefited from the recent application of learning theory and better anatomical knowledge of the connectivity of certain key neural structures, such as the nucleus accumbens. This progress has enabled the dissection of motivational processes into components that can begin to be related to the functioning of specific limbic cortical structures that project to different compartments of the ventral striatum.

Animals↗

PubMed1996

Effects of lesions to amygdala, ventral subiculum, medial prefrontal cortex, and nucleus accumbens on the reaction to novelty: implication for limbic-striatal interactions.

The effects of bilateral excitotoxic lesions of 3 major sources of afferents to the ventral striatum (nucleus accumbens) were compared on an open field test of food neophobia allowing the choice between familiar and novel food. Whereas lesions of the basolateral amygdala and ventral subiculum had qualitatively similar effects to reduce food neophobia (although not affecting the latency to eat), amygdala lesions increased and the ventral subiculum decreased locomotor activity. In contrast, damage to the ventromedial prelimbic prefrontal cortex only affected initial food choice and latency measures. By comparison, excitotoxic lesions of the nucleus accumbens itself and intra-accumbens infusion of the N-methyl-D-aspartate (NMDA) receptor antagonist AP5 increased activity and attenuated food neophobia. Results are discussed in terms of the role of limbic and prefrontal neuronal networks converging in the nucleus accumbens to control different aspects of the behavioral response to novelty.

Afferent Pathways↗

PubMed1996

Effects of excitotoxic lesions of the central amygdaloid nucleus on the potentiation of reward-related stimuli by intra-accumbens amphetamine.

The present study examined the effects of lesions of the central nucleus of the amygdala (CeA) on the acquisition of a new response with conditioned reinforcement (CR) and its potentiation by intra-accumbens infusions of d-amphetamine (1, 3, 10, and 20 microg/microl). Rats were trained to associate a light-plus-noise compound stimulus with the availability of a sucrose solution before receiving both bilateral ibotenic acid lesions of the CeA and cannulas implanted above the nucleus accumbens. Lesions of the central nucleus did not impair the performance of positively reinforced discriminated approach, nor did they impair the acquisition of a new response with conditioned reinforcement. However, the potentiation of responding with CR following intra-accumbens amphetamine was blocked in lesioned animals. These results are discussed in terms of the possible interactions between associative mechanisms in the amygdala and the mesolimbic dopamine projection.

Amygdala↗

PubMed1996

Dissociations in hippocampal 5-hydroxytryptamine release in the rat following Pavlovian aversive conditioning to discrete and contextual stimuli.

The experiments examined the release of 5-hydroxytryptamine using in vivo microdialysis methods in the hippocampus of freely moving rats following Pavlovian aversive conditioning to discrete and contextual stimuli. Differential conditioning was achieved by manipulating the interval between the offset of a discrete auditory 'clicker' stimulus and the onset of a mild foot-shock reinforcer (0.5 mA, 0.5 s). Foot-shock occurred either simultaneously with the last second of the discrete auditory stimulus (in short-trace subjects) or 60 s later (long-trace subjects). In this way, subjects were preferentially conditioned to the discrete stimulus and background 'contextual' stimuli respectively. During conditioning subjects also received two identical unpaired visual stimuli. At test, dialysates were collected and behavioural measures taken as all animals experienced (i) the aversive and two other 'neutral' environments, and (ii) the discrete unconditioned and conditioned stimuli presented in both aversive and neutral environments. Exposure to the aversive environment, but not to either of the two neutral environments, was associated with significantly increased hippocampal 5-hydroxytryptamine release in long-trace subjects. There was also a small but non-significant increase in 5-hydroxytryptamine release in short-trace animals. In contrast, hippocampal 5-hydroxytryptamine release was unaffected by presentation of either of the discrete stimuli under all conditions. The last result was obtained despite robust behavioural responses (freezing) to the discrete conditioned stimulus. These data do not agree with the hypothesis that aversive cues generally activate 5-hydroxytryptamine function in the hippocampus. Rather, they suggest a degree of specificity whereby 5-hydroxytryptamine release in the hippocampus was determined primarily by other qualitative properties of the conditioned aversive stimulus, namely whether the aversive cue was discrete or contextual, as well as by the magnitude of conditioning.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1996

Excitotoxic lesions of the basolateral amygdala impair the acquisition of cocaine-seeking behaviour under a second-order schedule of reinforcement.

In these experiments we sought to establish the intravenous (i.v.) self-administration of cocaine under a second-order schedule of reinforcement in order: (i) to obtain reliable, drug-free levels of responding with cocaine as a reinforcer, and (ii) to enable investigation of the neural mechanisms by which arbitrary cues gain motivational salience and, as conditioned reinforcers, control over drug-seeking behaviour. Initially, each infusion of cocaine was made contingent upon a response on one of two identical levers and was paired with a 20-s light conditioned stimulus (CS). Responses on the second lever were recorded, but had no programmed consequence. When rats acquired stable rates of self-administration, a second-order schedule of the type FRx(FRy:S) was introduced, with values of "x" being increased progressively to 10 and then "y" from 2 through 8. Priming (i.e. non-contingent) infusions of cocaine were never given. Once the first infusion was obtained under the second-order schedule, further infusions were made contingent on each response (to a maximum of ten infusions/day). Each stage was repeated daily until the first infusion of each session was achieved within a 5-min criterion. Rats with bilateral, excitotoxic lesions of the basolateral amygdala readily acquired the i.v. self-administration of cocaine under a continuous reinforcement schedule, initially administering more infusions and maintaining a slightly elevated level of self-administration than controls. Despite increased numbers of CS/drug pairings, basolateral amygdala-lesioned rats were severely impaired in the acquisition of the second-order schedule of i.v. cocaine reinforcement. Lesioned rats showed a cocaine dose-response function that was shifted upwards relative to control subjects. There was no significant difference between drug-naive amygdala-lesioned and control animals in the locomotor response to intraperitoneal injections of cocaine. These experiments indicate the feasibility and utility of second-order schedules in studying the neurobehavioural basis of cocaine-seeking behaviour. They suggest a dissociation in the neural mechanisms underlying cocaine-taking and cocaine seeking behaviour, and demonstrate the potential importance of the basolateral amygdala in the processes by which previously neutral stimuli gain control over drug-seeking behaviour.

Amygdala↗

PubMed1995

Differential effects of forebrain 5-hydroxytryptamine depletions on Pavlovian aversive conditioning to discrete and contextual stimuli in the rat.

The experiments examined the effects of depleting forebrain 5-hydroxytryptamine (5HT) on Pavlovian aversive conditioning to discrete and contextual stimuli. Rats were lesioned with intracerebroventricular injections of the neurotoxin 5,7-dihydroxytryptamine and then conditioned in a distinctive environment (termed the context) to a 30 s auditory stimulus. In 50% of animals the interval between the offset of the discrete auditory stimulus and the reinforcer, a mild foot-shock (0.5 mA, 0.5 s), was 5 s (the short-trace group) and in the other 50%, 30 s (the long-trace group). Theory predicts that animals in the short-trace condition will learn more about the discrete stimulus as a predictor of shock and become strongly conditioned, while those in the long-trace condition learn relatively more about the context. The extent of conditioning to the discrete and contextual stimuli was assessed separately, in extinction, using lick-suppression and place-preference measures respectively. Under these conditions sham subjects exhibited the expected dissociation with respect to trace interval. However, lesioned animals exhibited a specific impairment in contextual conditioning. The results are discussed in terms of the behavioural, neurochemical and neuroanatomical specificity of 5HT function in aversive conditioning and the implications for general theories of the role of 5HT in aversive processes.

Animals↗

PubMed1995

AMPA-induced lesions of the basal forebrain differentially affect cholinergic and non-cholinergic neurons: lesion assessment using quantitative in situ hybridization histochemistry.

The direct and transynaptic effects of lesions of the basal forebrain induced by alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and ibotenic acid were investigated using quantitative in situ hybridization histochemistry. Probes complementary to the sequences of choline acetyltransferase mRNA, glutamate decarboxylase mRNA and preproenkephalin mRNA were used to assess direct lesion effects within the basal forebrain and probes for postsynaptic M-1 and M-3 muscarinic receptors were used to assess long-term changes in neocortical muscarinic receptor mRNA expression following cholinergic deafferentation. AMPA-induced basal forebrain lesions destroyed significantly more neurons that expressed choline acetyltransferase mRNA than ibotenic acid-induced lesions (90 versus 60%), but significantly fewer neurons which expressed either glutamate decarboxylase or preproenkephalin mRNA (61 versus 83% reduction in glutamate decarboxylase mRNA and 56 versus 79% reduction in preproenkephalin mRNA). AMPA-induced lesions did, however, destroy a significant proportion of the neurons which expressed glutamate decarboxylase and preproenkephalin mRNA (approximately 60%). The neurons spared following AMPA-induced lesions were typically situated dorsolaterally within the dorsal pallidum, although neurons expressing glutamate decarboxylase or preproenkephalin mRNA were frequently observed within the areas of greatest cholinergic neuronal loss, i.e. the region of the nucleus basalis magnocellularis. These findings suggest that there is a population of non-cholinergic pallidal neurons which are insensitive to AMPA but not to ibotenic acid, reflecting a possibly heterogeneous distribution of NMDA and non-NMDA subtypes of glutamate receptors within the rat basal forebrain. AMPA-induced lesions of the basal forebrain were, however, without significant effect on the levels of expression of M-1 and M-3 muscarinic receptor mRNAs in the cerebral neocortex.

Animals↗

PubMed1995

The distribution of neurons coexpressing immunoreactivity to AMPA-sensitive glutamate receptor subtypes (GluR1-4) and nerve growth factor receptor in the rat basal forebrain.

The regional distribution of neurons containing alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor (GluR1-4) subunit immunoreactivity, relative to the distribution of cholinergic neurons within the basal forebrain of rats, was assessed using single- and dual-antigen immunocytochemistry. Analysis of serial sections stained with antibodies to nerve growth factor receptor (NGFr) and antibodies against each of the AMPA receptor subunits, GluR1-4, revealed a regional codistribution between NGFr- and GluR1- and GluR4-immunoreactive neurons in the medial septum, diagonal band nuclei and nucleus basalis magnocellularis. Quantitative dual-labelling immunocytochemistry using NGFr in combination with each of the GluR antibodies revealed > 65% colocalization between NGFr and GluR4 in each of the major cholinergic nuclei in the basal forebrain and 10-15% colocalization between NGFr, GluR1 and GluR2-3. The reticular nucleus of the thalamus, a structure known to be highly susceptible to AMPA-induced neurotoxicity, expressed GluR4 immunoreactivity exclusively. The observation that cholinergic neurons of the basal forebrain are also highly sensitive to AMPA and express the GluR4 subunit suggests that GluR4 may be important in AMPA receptor-mediated excitotoxicity.

Animals↗