Nestmate discrimination based on familiarity but not relatedness in eastern carpenter bees.

How animals recognize conspecific individuals has important outcomes in many contexts, but interactions among group members are particularly important. Two recognition criteria are often implicated in these interactions: kin recognition is based on relatedness cues and nestmate recognition is based on familiarity. For social insects, both types of recognition are possible, as many nestmates are close kin and familiarity can develop among individuals that encounter each other repeatedly. To discern whether social insects use kin or nestmate recognition, it is necessary to simultaneously assess how relatedness and familiarity influence behaviour. The facultatively social eastern carpenter bee, Xylocopa virginica, offers an excellent opportunity to study how either nestmate or kin recognition (or both) may influence interactions among nestmates, as many females disperse from their natal nests in spring, and often attempt to join new colonies that may contain unrelated individuals. This leads to frequent behavioural interactions among females that may be related or unrelated, and familiar or unfamiliar. We used observation nests and microsatellite loci to assess the influence of familiarity and relatedness on behavioural interactions during the early phase of colony development, when females establish reproductive queues prior to brood production. Females were more likely to feed and were less aggressive to familiar rather than related nestmates, regardless of their relatedness. This suggests that eastern carpenter bees primarily use learned cues to discriminate among nestmates. Interactions with nestmates were also context-dependent, as females returning to the nest without food were the recipients of more aggression than those returning with food. If spring dispersal leads to reduced relatedness in X. virginica colonies, then nestmate recognition based on familiarity would be an important factor in maintaining group cohesion.

Nesting habits influence population genetic structure of a bee living in anthropogenic disturbance.

While most organisms are negatively affected by anthropogenic disturbance, a few species thrive in landscapes altered by humans. Typically, native bees are negatively impacted by anthropogenic environmental change, including habitat alteration and climate change. Here, we investigate the population structure of the eastern carpenter bee Xylocopa virginica, a generalist pollinator with a broad geographic range spanning eastern North America. Eastern carpenter bees now nest almost exclusively in artificial wooden structures, linking their geographic distribution and population structure to human activities and disturbance. To investigate the population structure of these bees, we sampled females from 16 different populations from across their range. Nine species-specific microsatellite loci showed that almost all populations are genetically distinct, but with high levels of genetic diversity and low levels of inbreeding overall. Broadly speaking, populations clustered into three distinct genetic groups: a northern group, a western group and a core group. The northern group had low effective population sizes, decreased genetic variability and the highest levels of inbreeding in the data set, suggesting that carpenter bees may be expanding their range northward. The western group was genetically distinct, but lacked signals of a recent range expansion. Climatic data showed that summer and winter temperatures explained a significant amount of the genetic differentiation seen among populations, while precipitation did not. Our results indicate that X. virginica may be one of the rare 'anthrophilic' species that thrive in the face of anthropogenic disturbance.

How urban African American young adolescents spend their time: time budgets for locations, activities, and companionship.

The time budgets of a population of youth provide important information about their daily experience and socialization. This study reports data on the time budgets of a sample of 253 urban African American poor to working- and middle-class 5th-8th graders in Chicago. These youth were found to spend less time in school than other postindustrial adolescent populations, but spent no less time doing homework than White suburban U.S. young adolescents. They spent large quantities of time at home and with their families--at rates comparable to rates for young adolescents in a society with collectivist values like India. Unlike with other populations, early adolescence was not associated with major age changes in time allocations. Amount of time in schoolwork did not differ by grade, and amount of time with family did not show the decline with age that has been found for European American suburban adolescents.

The evolution of vertebrate antigen receptors: a phylogenetic approach.

Classical T cells, those with alpha beta T-cell receptors (TCRs), are an important component of the dominant paradigm for self-nonself immune recognition in vertebrates. alpha beta T cells recognize foreign peptide antigens when they are bound to MHC molecules on the surfaces of antigen-presenting cells. gamma delta T cells bear a similar receptor, and it is often assumed that these T cells also require specialized antigen-presenting molecules for immune recognition, which we term "indirect antigen recognition." B-cell receptors, or immunoglobulins, bind directly to antigens without the help of a specialized antigen-presenting molecule. Phylogenetically, it has been assumed that T-cell receptors and the genes that encode them are a monophyletic group, and that "indirect" antigen recognition evolved before the split into two types of TCR. Recently, however, it has been proposed that gamma delta-TCRs bind directly to antigens, as do immunoglobulins (Ig's). This calls into question the null hypothesis that indirect antigen recognition is a common characteristic of TCRs and, by extension, the hypothesis that all TCR gene sequences form a monophyletic group. To determine whether alternative explanations for antigen recognition and other historical relationships among TCR genes might be possible, we performed phylogenetic analyses on amino acid sequences of the constant and variable regions which encode the basic subunits of TCR and Ig molecules. We used both maximum-parsimony and genetic distance-based methods and could find no strong support for the hypothesis of TCR monophyly. Analyses of the constant region suggest that TCR gamma or delta sequences are the most ancient, implying that the ancestral immune cell was like a modern gamma delta T cell. From this gamma delta-like ancestor arose alpha beta T cells and B cells, implying that indirect antigen recognition is indeed a derived property of alpha beta-TCRs. Analyses of the variable regions are complicated by strong selection on antigen-binding sequences, but imply that direct antigen binding is the ancestral condition.

Behavioral reversal of lithium effects by four inositol isomers correlates perfectly with biochemical effects on the PI cycle: depletion by chronic lithium of brain inositol is specific to hypothalamus, and inositol levels may be abnormal in postmortem brain from bipolar patients.

The inositol depletion hypothesis of lithium (Li) action has been criticized, because depletion of inositol after chronic Li treatment has not been reproducible, effects of inositol to reverse Li-induced behaviors occurred also with epi-inositol, a unnatural isomer, and because inositol is ubiquitous in brain and hard to relate to the pathogenesis of affective disorder. Therefore, we review our studies showing that lithium depletion of brain inositol occurs chronically in the hypothalamus, a region not previously examined; that behavioral effects of four different inositol isomers including epi-inositol correlate perfectly with their biochemical effects; and that inositol in postmortem human brain is reduced by 25% in frontal cortex of bipolars and suicides as compared with controls. Because inositol in postmortem brain is reduced and not increased in bipolar patients, the relationship between inositol, lithium, and affective disorder is complex.

Developmental patterns and gender differences in the experience of peer companionship during adolescence.

Adolescents in fifth through eighth grade (N = 218) carried electronic pagers for 1 week and completed self-report forms in response to signals received at random times. Four years later, the sample underwent the same procedure. Results indicate that thinking about the opposite sex occurs at an earlier age than spending time with the opposite sex alone and that both increase over time. Results also indicate little change in same-sex companionship over time. Girls spent more time with the opposite sex and spent more time thinking about opposite- and same-sex peers. Time with the opposite sex alone was experienced as very positive, whereas time spent thinking about the opposite sex was associated with less positive states as adolescents became older.

Epi-inositol is biochemically active in reversing lithium effects on cytidine monophosphorylphosphatidate (CMP-PA). Short communication.

In CHOm3 cells and rat cerebral cortex slices, epi-inositol was less potent but as effective as myo-inositol in reversing carbachol/lithium-stimulated CMP-PA accumulation whereas L-chiro- and scyllo-inositol were less active or inactive. These results with the four inositol isomers in two tissues correlate exactly with their effects on lithium-pilocarpine induced seizures and suggest a common mechanism of action for biochemical and behavioural effects.

Human muscarinic receptors expressed in A9L and CHO cells: activation by full and partial agonists.

1. A comparative study of receptor activation by ten full and partial muscarinic agonists was undertaken on the five subtypes of human muscarinic receptors expressed at similar receptor densities in Chinese hamster ovary (CHO-K1) cells. In addition, m1, m2 and m3 receptors were expressed in mouse fibroblast A9L cells in order to compare the influences of cell type on agonist activation of these receptors. 2. Receptor-effector coupling efficiencies were greater in CHO than A9L cells and agonists displayed greater potencies and similar or greater intrinsic activities at CHOm1 and CHOm3 than A9Lm1 and A9Lm3 receptors. Although m2 receptor density was 6 fold higher in A9L than CHO cells, carbachol elicited significantly greater inhibition of adenosine 3':5'-cyclic monophosphate (cyclic AMP) formation in CHOm2 cells. These data suggest that not only receptor density but receptor-effector coupling and/or coupling efficiencies play significant roles in agonist-induced responses. 3. In CHO cells, receptor-effector coupling efficiencies were m3 = m1 > m5. Although CHOm5 receptors were the least efficiently coupled, some partial agonists displayed higher intrinsic efficacies at m5 than m3 receptors suggesting that, in CHO cells, m5 and m3 receptors may activate different G proteins and/or effectors to stimulate inositol monophosphate (IP1) formation. 4. McN-A-343 was a functionally selective m4 agonist. It had little or no agonist activity at m3 receptors expressed in either A9L or CHO cells. The slopes of McN-A-343 concentration-response curves inCHOm2 cells were significantly lower than the slopes obtained with this compound in CHOm4 cells suggesting that the mode of activation by McN-A-343 differed between the two muscarinic receptors negatively coupled to adenylyl cyclase.5. Cloned receptors provide valuable tools for the study of agonist-receptor interaction and agonist receptor activation but caution should be applied in assuming that the results are valid for all cell types or for tissue-expressed receptors.

Differences in agonist potency ratios at human m1 muscarinic receptors expressed in A9L and CHO cells.

A9L mouse fibroblast and Chinese hamster ovary (CHO) cells appear to differ in their complement of guanine-nucleotide binding proteins (G proteins) and/or isoform of effectors that lead to inositol-monophosphate formation. The influence of these cellular components on receptor activation was examined by comparing agonist-induced inositol monophosphate formation via human muscarinic m1 receptors expressed in the two cell lines. The rank order of agonist potencies of five full agonists differed in the two cell lines. In addition, differences in agonist potency ratios for two of the five agonists (carbachol and methacholine) suggest that the agonists differ in their activation of m1 receptors and this is reflected in differences in G protein coupling. The results provide biological evidence that muscarinic agonists differentially activate m1 receptors and that, at least for the systems examined in this study, receptor-effector coupling in a given system may depend on the structure of the agonist.

Divergent worlds: the daily emotional experience of mothers and fathers in the domestic and public spheres.

This study compared the emotional states experienced by mothers and fathers during daily activities in the domestic and public spheres. Participants carried pagers for 1 week and reported their states when signaled at random times. Patterns for mothers and fathers differed markedly. Mothers reported more positive states in activities away from home, including during work at a job. These states were related to the perceived friendliness of co-workers. Fathers reported more positive states in the home sphere, partly because they spent more of this time n personal and recreational activities and partly because they experienced more choice, even during family work.

The relationship of maternal employment to early adolescent daily experience with and without parents.

This study examines how maternal work may shape pre- and young adolescents' daily life experience. According to the procedures of the Experience Sampling Method (ESM), 295 10-13-year-old children carried electronic pagers for 1 week and completed self-report forms in response to random signals sent every other hour. Their daily experience did not differ by maternal employment status, with the following exceptions: full-time maternal employment was associated with more time doing homework with mothers and less time in general leisure, while part-time employment was associated with more time doing sports with parents. Relative to those with nonemployed mothers, youth with part-time employed mothers reported more positive daily moods and higher self-esteem, while youth reported time with full-time employed mothers to be the friendliest. While children with employed mothers spent no less time with family, parents, friends, in class or alone, they spent more time alone with fathers.

Daily companionship in late childhood and early adolescence: changing developmental contexts.

The study employs time-sampling data to examine age differences in the quantity and quality of children's and young adolescents' daily experience with their families, friends, and alone. Participants (ages 9-15) carried electronic pagers for 1 week and reported their companionship, location, and affect at random times when signaled by the pagers. Findings show a dramatic decline in amount of time spent with family, with older students reporting half as much time with their families as younger students. Among boys, this family time was replaced by time spent alone; among girls, by time alone and with friends. Affect reported when with family became less positive between the fifth and seventh grade, but was more positive again in the ninth grade for boys. Affect with friends became more favorable across this age period; affect when alone did not vary. These age differences suggest changes in adolescents' daily opportunities for cognitive growth, emotional development, and social support.

Effects of cyproheptadine and pizotifen on central muscarinic receptors.

The affinities of cyproheptadine, pizotifen and (+/-)-quinuclidinyl xanthane-9-carboxylate hemioxylate (QNX) were determined at muscarinic autoreceptors and postsynaptic (IP1 formation) receptors in rat hippocampal slices. The affinity values for QNX were 8.2 and 8.5 respectively. Cyproheptadine and pizotifen were less potent than QNX. Pizotifen was slightly (2-fold) less active at antagonizing IP1 formation than blocking the autoreceptors whereas cyproheptadine was equally active at antagonizing the two hippocampal muscarinic receptors.

Long term effects of septohippocampal lesions and intrahippocampal grafts on acetylcholine concentration, muscarinic stimulated formation of inositol phospholipids and electrically evoked release of neurotransmitters in the rat hippocampus.

Long Evans female rats sustained aspirative lesions of the septohippocampal pathways; subsequently, they received intrahippocampal suspension grafts of fetal septal-diagonal band or hippocampal tissue. The long term (8-10 months post-surgery) effects of these treatments were examined in the hippocampus for the following variables: concentration of hippocampal acetylcholine (ACh), muscarinic-stimulated (carbachol) formation of inositol monophosphate, accumulation of tritiated choline, noradrenaline (3H-NA) and serotonin (3H-5-HT), electrically evoked release of 3H-acetylcholine (3H-ACh), 3H-NA and 3H-5-HT, and choline acetyltransferase (ChAT) activity. The lesions decreased the levels of endogenous ACh, the accumulation of 3H-choline and 3H-5-HT and the evoked release of both 3H-ACh and 3H-5-HT as well as the ChAT activity, but they failed to significantly affect the muscarinic-stimulated formation of inositol monophosphate and the accumulation and release of 3H-NA. Grafts of hippocampal cells were found to be ineffective on all lesion-induced effects. In contrast, grafts of septal-diagonal band origin attenuated the deficit of hippocampal concentrations of ACh and accumulation of 3H-choline without, however, improving release of 3H-ACh, accumulation and release of 3H-5-HT, and ChAT activity. These observations suggest that: (i) denervation-induced hippocampal muscarinic supersensitivity might not be long-lasting or the lesions, which in some cases spared the lateral edges of the fimbria, failed to induce any muscarinic supersensitivity, (ii) intrahippocampal grafts rich in cholinergic neurons do not foster recovery from the lesion-induced noncholinergic deficits we assessed, (iii) recovery of function may be expressed by some but not all biochemical or pharmacological cholinergic variables and (iv) graft-derived hippocampal reinnervation may be less efficient than the endogenous innervation of intact rats as indicated by the restoration of only some of the variables related to cholinergic function by intrahippocampal septal-diagonal band grafts.

Endothelin-1 binding sites and inositol-monophosphate formation in kidney medulla from adult and juvenile SHR and WKY rats.

High resolution autoradiography at the cellular level localized endothelin-1 binding sites to the collecting ducts in the rat renal papilla. These receptors were functionally coupled to the phosphatidyl-inositol system since endothelin-1 stimulated the accumulation of IP(1) in a concentration-dependent manner in cross chopped slices from renal papillae. The concentration-effect curves in 4 week old normotensive Wistar-Kyoto rats (WKY) lay to the right of curves from 4 week old and adult spontaneously hypertensive rats (SHR) and adult WKY (20-24 week old) animals; the EC(50) values in the 4 week old animals were 17 +/- 5 and 8 +/- 1 nM (P < 0.05, n = 5; mean +/- SE) for the normotensive and hypertensive animals, respectively. Autoradiographic studies showed that the density and distribution of binding sites for [(125)I]endothelin-1 in the kidneys did not differ between the groups; receptor densities in the renal papillae were 461 +/- 37 (fmol/mg protein) in the 4 week old WKY, and 443 +/- 27 (fmol/mg protein) in the 4 week old SHR. The plasma levels of immunoreactive endothelin-1 were also similar between groups; 4 week old SHR (39 +/- 3 pg/ml) and 4 week old WKY (36 +/- 1 pg/ml). The increased response to endothelin-1 may be related to the development of the hypertensive state in the SHR.

Relative potencies of agonists and differential sensitivity to N-ethylmaleimide on muscarinic autoreceptors and postsynaptic receptors in rat hippocampus.

Relative potencies of nine muscarinic agonists as activators of autoreceptors regulating [3H]acetylcholine release or of postsynaptic receptors, stimulating inositol monophosphate (IP1) formation were determined in rat hippocampal slices. The agonists could be divided into three groups: 1) full agonists at both sites included oxotremorine-M, carbachol and methacholine; 2) full agonists at autoreceptors and partial agonists at receptors coupled to IP1 formation included oxotremorine, arecoline, bethanechol and RS-86; 3) McN-A-343 was a partial agonist at both sites. Arecaidine propargyl ester was a full agonist at autoreceptors but produced a biphasic stimulation of IP1 formation. Comparison of the EC50 values showed that agonists of groups 1 and 3 were more potent at autoreceptors than at IP1-coupled receptors. Group 2 agonists displayed similar potencies at the two types of receptors. N-Ethylmaleimide (NEM) was more active in antagonizing autoreceptors than IP1-coupled receptors in rat hippocampus. Concentration-response curves to carbachol at autoreceptors were shifted to the right in the presence of 10 microM NEM; 30 microM NEM reduced the maximal response. At postsynaptic receptors, higher concentrations of NEM (100 and 120 microM) were required for inhibition of maximum stimulation of IP1 by carbachol. NEM at 160 and 300 microM abolished the stimulation of IP1 induced by carbachol. These observations provide additional evidence that muscarinic autoreceptors differ from the postsynaptic muscarinic receptors that modulate IP1 formation. The similar rank order of agonist potencies between hippocampal autoreceptors and cardiac muscarinic receptors supports the hypothesis that these autoreceptors are of the M2 (cardiac) subtype.

Weight and eating concerns among pre- and young adolescent boys and girls.

The emergence of weight and eating concerns in pre- and young adolescents and the relations of these concerns to daily experience and psychologic adjustment were investigated. Four hundred eighty-one children from fifth to ninth grades completed a Weight and Eating Concerns Scale, a depression inventory, self-esteem and body image scales, and reported their daily experiences by the Experience Sampling Method. Girls tended to report more weight and eating concerns than boys. This discrepancy increased with age. In older girls (eighth and ninth graders) extreme weight and eating concerns were associated with other signs of emotional maladjustment. Girls who experience emotional distress may try to compensate for the strain by controlling body shape and in doing so, may place themselves at risk for developing an eating disorder. Boys currently appear to be protected from this difficulty. Our findings suggest that excessive weight and eating concerns in young adolescent girls signal psychologic maladjustment which may require attention.

Rat hippocampal muscarinic autoreceptors are similar to the M2 (cardiac) subtype: comparison with hippocampal M1, atrial M2 and ileal M3 receptors.

1. Affinity constants for 15 non-selective or putatively selective muscarinic antagonists were determined at muscarinic autoreceptors and postsynaptic receptors (linked to phosphatidylinositol (PI) hydrolysis) in rat hippocampal slices, at muscarinic receptors mediating contractility in guinea-pig atria or ileal smooth muscle and at binding sites in rat cerebral cortical membranes labelled with [3H]-1-quinuclidinyl benzilate or [3H]-pirenzepine. 2. Comparison of the affinities of these antagonists at central M1 receptors (inositol-monophosphate formation in rat hippocampal slices) with their affinities at peripheral M1 receptors (inhibition by McN-A-343 of electrically stimulated twitches in rabbit vas deferens) provides support for the suggestion that these receptors may differ pharmacologically. 3. Comparison of affinity constants obtained by displacement of specifically bound [3H]-pirenzepine from rat cerebral cortical membranes with those obtained in functional tests showed poor correlations between affinities for binding sites and for functional atrial receptors or for hippocampal autoreceptors. A significant correlation was found between affinities for [3H]-pirenzepine binding and those determined at muscarinic receptors linked to PI turnover in rat hippocampus. A significant correlation was also obtained between the affinities for specific [3H]-pirenzepine binding sites in cortical membranes and the affinities at ileal receptors. 4. Comparison of the affinity values for muscarinic autoreceptors in rat hippocampus with affinity values obtained from in vitro models of muscarinic receptor subtypes showed no significant correlations between these autoreceptors and either M1 or M3 receptors. A significant correlation was found between antagonist affinities for hippocampal autoreceptors and muscarinic receptors in the heart. Therefore, muscarinic autoreceptors in rat hippocampus are pharmacologically similar to the M2 (cardiac) muscarinic receptor subtype.