Peter Kabai

Feeding innovations and forebrain size in Australasian birds

Many authors have proposed that behavioural flexibility in the field is associated with learning ability in captivity, relative forebrain size and rate of structural evolution. In birds, the frequency of feeding innovations reported in the short notes sections of ornithology journals may be a good way to operationalize flexibility. In this paper, we examine in the birds of Australia and New Zealand the relationship between forebrain size and innovation frequency found in a previous study covering North America and the British Isles. From a methodological point of view, the two variables are highly reliable: innovation frequency per taxonomic group is similar when different readers judge innovation reports and when different editorial styles govern journals; relative forebrain size yields very similar estimates whether mean residuals from a log-log regression are used or ratios of forebrain to brainstem mass. Innovation frequency per taxon is correlated between the two Australasian zones and between these zones and the more northerly ones studied previously. Innovation frequency is also associated with relative forebrain size in Australia and, to a lesser extent, in New-Zealand; in Australia, parrots show the high frequency of innovations predicted by their large forebrain, but yield no innovations in the New Zealand sample. The forebrain/innovation trend is independent of juvenile development mode, but phylogeny appears to be an important intervening variable in Australasia, as evidenced by non-significant independent contrasts.

Efferent connections of the domestic chick archistriatum: A phaseolus lectin anterograde tracing study

The archistriatum of the domestic chick has been implicated in both fear behaviour and learning. However, relatively little is known about its organisation. The efferent connections of discrete anatomical regions of the chick archistriatum were therefore investigated by iontophoresis of the anterograde tracer Phaseolus vulgaris leucoagglutinin into its anterior, dorsal intermediate, ventral intermediate, medial, and posterior parts. The results of this study suggest that the chick archistriatum can be divided into two basic divisions according to whether they project to the following limbic structures: the hippocampal formation, septal areas, lobus parolfactorius, nucleus accumbens, ventral paleostriatum, and dorsomedial thalamus. The limbic archistriatum includes the posterior archistriatum and extends rostrally through the ventral intermediate archistriatum into the anterior archistriatum. The non‐limbic archistriatum comprises the dorsal intermediate and medial archistriatum and largely gives rise to specific sensory, somatosensory, and motor telencephalofugal efferents. There may not be distinct borders between these two divisions of the chick archistriatum. J. Comp. Neurol. 389:679–693, 1997.

The involvement of dopamine in the striatum in passive avoidance training in the chick

Quantitative receptor autoradiography was used to investigate the distribution of binding of [3H]SCH 23390 to dopamine (D1) and [3H]spiroperone to D2 receptors in regions of the forebrain of the one-day-old domestic chick (Gallus domesticus). High levels of specific binding of the D1 and D2 ligands were found in the striatal regions (paleostriatum augmentatum and lobus parolfactorius) of the one-day-old chick, as reported previously in the pigeon, turtle and rat, whilst binding levels were considerably lower in the pallidum (paleostriatum primitivum), hippocampus and hyperstriatum ventrale. The proportions of D1 and D2 receptor binding in the chick were relatively similar in the striatum and pallidum, apart from the paleostriatum augmentatum, where D2 receptors outnumber those of D1 by a factor of two. Binding of the D1 and D2 ligands to forebrain regions was also investigated 30 min after one-trial passive avoidance training of one-day-old chicks in which the aversive stimulus was a bead coated with a bitter tasting substance, methyl anthranilate. These experiments demonstrated a large and highly significant bilateral increase (compared to control birds) in binding to D1 (but not D2) receptors in the lobus parolfactorius. In this striatal region, equivalent to the caudate-putamen of mammals, previous studies have shown that synaptic and dendritic alterations occur following avoidance training. It is concluded that alterations in dopamine binding may be involved in processes that result in modification of the pecking response in chicks after avoidance training.

Inhibiting effect of D1, but not D2 antagonist administered to the striatum on retention of passive avoidance in the chick

The avian lobus parolfactorius, equivalent to the medial striatum (caudate-putamen) of mammals, has been shown to be of crucial importance in passive avoidance training in day-old domestic chicks, where the aversive stimulus is the bitter tasting substance methylanthranilate. Here we report that the specific D1 antagonist SCH23390, injected into the lobus parolfactorius of day-old chicks (Gallus domesticus) prior to training, impaired performance on testing 30min post-training at low doses (0.5 and 25nmol). Sulpiride, a D2 antagonist, had no significant effect on performance in comparable doses. The early D1 activation may signify an essential mechanism leading to storage itself or to the canalisation of the relevant association to a permanent store.

Changes in binding to muscarinic and nicotinic cholinergic receptors in the chick telencephalon, following passive avoidance learning

Changes in nicotinic and muscarinic cholinergic receptors 30 min after one-trial passive avoidance training were studied in day-old chicks (Gallus domesticus), by quantitative receptor autoradiography. [3H]-alpha-bungarotoxin (alpha-BgT) and [3H]-quinuclidinyl benzilate (QNB) were used to monitor changes in 15 forebrain regions for nicotinic and muscarinic receptors, respectively. A significant increase occurred bilaterally in the quantity of bound alpha-BgT in the lobus parolfactorius, while the amount of bound QNB decreased significantly, and bilaterally, in the hippocampus, hyperstriatum ventrale, lobus parolfactorius and posterolateral telencephalon, pars dorsalis. The data support an involvement of cholinergic receptor types in the neural mechanisms underlying passive avoidance learning.

Transfer of brain dopamine system-specific quantitative trait loci onto a C57BL/6ByJ background

1Laboratory of Neurobehavioral Genetics, Nathan S. K1ine Institute, 140 Old Orangeburg Road, Orangeburg, New York 10962 2Department of Psychiatry, New York University Medical Center, 550 First Avenue, New York, New York 10016 3Research Genetics, 2130 Memorial Parkway, S.W., Huntsville, Alabama 35801 4Unit on Neurotoxicology & Neuroprotection, Laboratory of Clincal Science, NIMH, Bethesda, Maryland 20892 5Department of Psychiatry, Mt. Sinai School of Medicine, New York, NY 10029 61st Institute of Biochemistry, Semmelweis University Medical School, Budapest, H-1088, Hungary 7Research Department, Meninger Clinic, Box 829, Topeka, Kansas 66601 8Pharmacological Research Center, Chemical Works of Gedeon Richter Ltd., P. O. Box 27, Budapest, H-1475, Hungary 9Energotechno, Budapest, H-1024, Hungary

Analysis of the Mesotelencephalic Dopamine System by Quantitative-Trait Locus Introgression

One of the significant factors that affect brain dopamine function is the activity of tyrosine hydroxylase (TH), the first and rate-limiting enzyme in catecholamine biosynthesis. For the analysis of the genetically determined role of dopamine function and TH in behavior and in the regulatory mechanisms of the mesotelencephalic dopamine system we devised a novel genetic strategy (Vadasz; Mouse Genome 88:16–18; 1990). We hypothesized that phenotypic introgression and recombinant fixation could ensure the transfer of Quantitative Trait Loci (QTL) from one strain onto the genetic background of another strain, and new, genetically very similar quasi-congenic strains could be created that would carry individual QTLs, or QTLs in various combinations. Here we summarize the construction of the first set of QTL Introgression strains, and present evidence that QTLs that are responsible for the continuous variation of mesencephalic tyrosine hydroxylase activity (TH/MES), have been transferred onto the C57BL/6By (B6) strain background from BALB/cJ (C) and CXBI (I) donor strains with high and low TH/MES, respectively. The QTL transfer was carried out in two directions by repeated backcross-intercross cycles with concomitant selection for the extreme high and low expressions of TH/MES in replicates, resulting in four QTL Introgression lines. Analysis of regional brain TH activities in the course of the QTL introgression indicated that (a) TH activity in B6.I lines showed quite limited heritability, (b) TH/MES was not highly correlated with striatal TH, and (c) the control of hypothalamic and olfactory tubercle TH activities was largely independent from that of TH/MES. Examination of the open-field (OF) behavior data demonstrated that TH activity did not correlate significantly with OF behavior. After 5 backcross-intercross cycles, TH/MES in each replicate line was still significantly different from that of the B6 background strain. A genomewide scanning of microsatellite markers in the QTL introgression lines demonstrated that about 96% of the markers were of background (B6) type. These results indicate the successful transfer of TH/MES QTLs. After the QTL transfer phase of the experiment altogether more than 100 new RQI strains were initiated in the QTL Introgression lines by strict brother × sister mating. After fixing the introgressed QTLs, ten of the inbred RQI strains were tested for TH/MES. The results showed that in one of the new RQI strains TH/MES was restored to a level that is characteristic to the C donor strain, while TH/MES values in some other strains were between those of the background and donor strains, confirming our hypothesis that phenotypic introgression and recombinant fixation can ensure a virtually complete transfer of QTLs. We conclude from this study that complex, continuously distributed neural traits can successfully be subjected to QTL introgression, and the results raise the possibility that the RQI method can be efficiently applied for gene mapping of complex neural and behavioral traits even if their phenotypic expression is sensitive to confounding developmental and environmental variations, genetic interactions, and genotype-environment interactions.

Subtelencephalic visual discrimination in selected lines of japanese quail

We studied visual discrimination capabilities of the avian brain stem in genetic lines of Japanese quail artificially selected for unconditional approach preference for blue, red or an achromatic pattern stimulus. Complete telencephalectomy did not abolish approach behavior and visual discrimination. Our data indicate that visual feature extraction and motor coordination related to early approach preferences in birds may be mediated by brain stem and thalamic circuitries which do not require input from higher level visual and motor regions.

Context-dependent prey avoidance in chicks persists following complete telencephalectomy.

Young naive domestic chicks readily attack green insects and avoid insects painted red but show no discrimination of the same colours when applied to fruit-like objects, a discrimination that has been depicted as context-dependent preference. To study the neural representation of such preference we performed bilateral telencephalectomy on 1-day-old domestic chicks and tested them on an unlearned prey discrimination paradigm. Here we show that following complete decerebration, young domestic chicks preferentially peck at red fruit versus red insects and tend to choose green insects over green fruit indistinguishably from unoperated chicks. The present study provides the first direct evidence that sophisticated context-dependent, unlearned colour preference is processed by subtelencephalic areas of an amniote species.

Methamphetamine-Induced Stereotypies in Newly-Hatched Decerebrated Domestic Chicks

Metamphetamine in high dose has been reported to induce stereotypic behavior of abnormal form in the pigeon and domestic chick. A number of reports suggested that the target of metamphetamine was the paleostriatal complex, the highest motor center of the avian brain. The present study tested this hypothesis by treating newly-hatched domestic chicks with high dose of metamphetamine (10 mg/kg b.w.) after complete decerebration or sham operation. Stereotypic mandibulations were observed both in sham-operated and in decerebrated birds in similar form following methamphetamine treatment. The results suggested that brainstem pattern generators remain responsive to dopaminergic stimuli in the absence of the main telencephalic (striatal) targets.