Extension of the CS past the US can facilitate conditioning of the rabbit's nictitating membrane response

Five experiments were conducted in which the onset of a tone conditioned stimulus (CS) preceded the unconditioned stimulus (US) by 500 ms. Across experiments, the offset of the CS was extended past the offset of the US by values ranging from 0 ms to 40000 ms. Extensions of the CS of 2000 ms or greater produced acquisition of a conditioned response (CR) that was as fast or faster than in the no-extension condition (0 ms). While extension of a forward tone CS after the US enhanced excitatory conditioning, insertion of another CS (light) in a purely backward relationship with the US passed only a retardation test, indicative of latent inhibition, and not a summation test needed for conditioned inhibition. The results add to the evidence that excitatory and inhibitory processes are both engaged following US offset. Alternative theories of CS processing are discussed.     

Reaction time task as unconditional stimulus. Comparing aversive and nonaversive unconditional stimuli

Nonaversive unconditional stimuli (USs) are seldom used in human classic conditioning of autonomic responses. One major objection to their use is that they produce deficits in electrodermal (ED) second- and third-interval response conditioning. However, a nonaversive reaction time (RT) task that includes feedback of success has been shown to be an effective US while avoiding this disadvantage (Lipp and Vaitl 1988). The present study compared this new RT task (RT-new) with a traditional RT task (RT-old) and with a standard aversive US (shock) in differential classic conditioning of ED, heart rate (HR), and digital pulse volume (DPV) responses. Eight-second-delay differential conditioning was applied in three groups of 12 subjects each. Simple geometric features (square, cross) displayed on a television screen served as conditional stimuli (CS+ and CS-). In acquisition, there were no statistically significant differences among the groups; differential conditioning did occur in HR, first- and second-interval ED responses, and first-interval DPV responses. Separate analyses within each group, however, revealed that there was no second-interval ED conditioning in the RT-old group. During extinction, neither DPV nor second-interval ED conditioning could be obtained, whereas HR and first-interval ED conditioning occurred in each group. In third-interval omission ED responses, RT-old and shock groups exhibited extinction, while response differentiation was maintained in the RT-new group throughout extinction. The RT task including feedback proved to be as reliable a US as a standard aversive US, whereas application of a traditional RT task again yielded some weaknesses in second-interval ED conditioning.     

Reaction time task as unconditional stimulus. On conditioning skin conductance responses and heart rate, using a nonaversive unconditional stimulus

The present study was conducted to demonstrate classic conditioning in electrodermal (ED) and heart rate (HR) responses by using a nonaversive reaction time (RT) task as unconditional stimulus (US). Three groups of 12 subjects each were studied to test the efficacy of this US procedure by varying the essential components of the RT task-US between groups. Eight seconds differential delay conditioning was applied in each group. Simple geometric features (square, cross) displayed on a TV screen were used as CS+ and CS-. RT task consisted of a nonaversive tone (72 dBA, 1000 or 1200 Hz) and a motor response (pressing a button with the left index finger). Subjects were asked to respond as soon as the tone stimulus was presented. The three groups received different stimulus sequences during the 16-trial acquisition phase only. In one group (Group C1), CS+ was followed by a tone to which subjects were to respond, whereas CS- was not followed by a tone. Similarly, in a second group (Group H), CS+ was followed by a tone, whereas CS- was not; however, subjects of Group H (habituation group) were not required to respond to the tone. In a third group, (Group C2) CS+ was followed by a tone to which subjects were to respond, while CS- was followed by a different tone requiring no response. According to analysis of Group C1 data, differential conditioning was obtained in each response measure. Group H displayed habituation in each response measure obtained. In Group C2, differential conditioning was obtained in the second latency window of ED responses only.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pavlovian conditioning of lung anaphylactic response in rats

The present experiment was undertaken to verify if it is possible to impose Pavlovian conditioning on a lung anaphylactic response (LAR) in rats. Two experiments were done. In the 1st, egg albumin (OVA) aerosol inhalation, which induces signs and symptoms of LAR in OVA- sensitized rats, was paired with an audiovisual cue (conditional stimulus, CS). After reexposure to the CS, the signs and symptoms of LAR were quantitatively measured using a scoring system specially developed for this evaluation; the levels of stress response and anxiety were also quantified. Results showed that the rats reexposed to CS only, displayed LAR scores not significantly different from those reexposed to both CS and the antigen; animals of these groups showed significantly higher LAR scores than rats that received no OVA aerosol challenge. High levels of stress and anxiety were observed 30-40 min after the challenge with OVA aerosol. In the 2nd experiment, rats sensitized with OVA and submitted or not to Pavlovian conditioning were observed in the open-field and in the plus maze apparatus in the absence of OVA aerosol but in the presence of the CS; after behavioral observations the animals were sacrificed for serum corticosterone level determination. Both behavioral and biochemical data showed high levels of stress and anxiety in rats for which the antigen was previously paired with the CS; these changes were not observed in animals which received the antigen 24 h after the presentation of the CS (unpaired) or in those exposed to PBS aerosol (the OVA vehicle) only. The present data show not only that LAR can be submitted to Pavlovian conditioning, but also and importantly, that high levels of stress and anxiety are related to the course of LAR.     

Tonic and phasic stimulus control of blood pressure responses using opposing unconditional stimuli

The transswitching paradigm was used in the present study to investigate the effects of tonic (long duration) environmental stimuli paired with opposing unconditional stimuli on human blood pressure. Sixty volunteers participated for two sessions, one week apart. Subjects were presented with a pseudorandom sequence of four trials of red lights (five minutes each) and four trials of blue lights (five minutes each) within each session. All subjects received the cold pressor test during the red lights. During the blue lights, half the subjects received warm water and the other half received a neutral temperature water. Subjects received the presentations of the water in one of three methods: as determined by the experimenter, preceded by a warning signal, or self-administered. The results indicated that conditional and unconditional responses during the red lights were progressive increases in blood pressure. During the blue lights associated with warm water, conditional and unconditional responses were often progressive decreases in blood pressure. The method of administration of the water affected the magnitude of the unconditional responses. Evidence for phasic stimulus control was not as unequivocal as tonic stimulus control. The present results indicated that it is possible to modify blood pressure in two directions (increases and decreases) when two high contrast, opposing unconditional stimuli are presented.     

Latent inhibition as a function of CS intensity in taste aversion learning

An experiment is reported in which the relationship between the intensity of a preexposed stimulus and latent inhibition was investigated, using the taste aversion learning paradigm in rats. Two concentrations of a saline solution (high, 1%; and low, 0.25%) were used during preexposure and conditioning phases in a factorial design. Two control conditions without preexposure were added, one for each stimulus concentration during conditioning. The known effect of conditioned stimulus (CS) intensity during conditioning was confirmed: the more concentrated the solution used in conditioning, the higher the acquisition rate. A direct relationship was observed between the CS intensity used during preexposure and the latent inhibition effect: the more concentrated the solution during preexposure, the lower the acquisition rate of conditioning. The implications of these results for latent inhibition theories are considered.     

Stress response to acoustic stimuli in an aphid: A behavioral bioassay model

The green peach aphid, Myzus persicae (Sulzer), feeds consistently and regularly throughout all stages of nymphs and adult. That is, honey dew production, which indicates a state of feeding, occurs at regular intervals within a given stage, and moving, which interrupts feeding, tends to occur rarely. We used these behaviors to test whether sound stimuli acted as a stress in this species. We conducted the playback experiment in which acoustic stimuli with a combination of five frequencies (100, 500, 1000, 5000, and 10000 Hz) and three intensity levels (66, 78, 90 dB SPL) were presented to all stages of aphids. Under all acoustic stimuli, honey dew production occurred less often, and moving occurred more often and for longer. The results of two‐way multivariate analysis of variance showed that the stimulus frequency was a significant factor for variation in aphid behaviors in the playback experiment. However, there was no intensity effect on the aphid's behavior. Based on the electrical penetration graph experiment, aphid feeding stopped frequently and lasted only for short durations under acoustic stimuli. The results of both experiments demonstrated that the acoustic stimuli were effective in inducing feeding suppression in this species. Thus, the acoustic stimuli may be a stressor in the green peach aphid. Furthermore, the behavioral bioassay employed in this study may be used to assess the effect of various stressors on aphids.     

Differences in the taste quality of maltose and sucrose in rats: issues involving the generalization of conditioned taste aversions

The present study employed a conditioned taste aversion generalizationparadigm to test the hypothesis that maltose produces tastesensations in the rat which are qualitatively distinguishablefrom sucrose. Since stimulus generalization can occur in boththe quality and intensity domains, an intrachemical (acrossconcentration) generalization gradient was established to aidin the interpretation of the interchemical (across molecules)generalization gradient. Moreover, since the commonly used intaketest is vulnerable to nontaste post-ingestional influences,the present study measured immediate responses to 100 µlstimulus samples, thus increasing our confidence that the behaviorwas under orosensory control. In Experiment 1, naive water deprivedrats were trained in a specially designed gustometer to maintaindrinking-spout contact for intermittent water reinforcement.Following this, rats in the experimental group were given threeexposures to 0.1 M sucrose on separate days, with the firsttwo exposures immediately preceding an injection of LiCl. Acontrol group was treated identically but received distilledwater instead of sucrose. Rats were then tested in the gustometerfor their avoidance of three equimolar concentrations of sucroseand maltose. Rats received ten trials of each stimulus quasi-randomlypresented in two sessions. Results indicated that all sucroseconcentrations were avoided (in experimental group only), butonly the 0.3 M concentration of maltose was avoided. The lowestsucrose concentration was significantly less avoided than thehigher concentrations. Intensity generalization gradients aresuch that intensities weaker than the conditioned stimulus (CS)produce just as much or less of a conditioned response (CR)and intensities stronger than the CS produce just as much ora greater CR than that elicited by the CS itself. Therefore,based on the results of Experimental, it was predicted thatif 0.1 M maltose served as the CS, the order of avoidance shouldbe: 0.3 M sucrose 0.1 M sucrose 0.03 M sucrose 0.3 M maltose 0.1 M maltose 0.03 M maltose, if it were true that maltoseand sucrose produce identical sensations that differ only inintensity. Experiment 2 explicitly tested this prediction usingthe same procedure as Experiment 1 except that 0.1 M maltoseserved as the CS. The observed order of avoidance was 0.3 Mmaltose > 0.1 M maltose > 0.03 M maltose = 0.3 M sucrose= 0.1 M sucrose = 0.03 M sucrose. In both experiments the intrachemicalgeneralization gradient broadened and the interchemical generalizationgradient steepened upon retesting. In conclusion, qualitativedifferences between maltose and sucrose explain the outcomesof these experiments better than differences in the relativeintensity of these sugars at isomolar concentrations.     

Correlation of neuronal reactions of different regions of the neocortex of the rabbit to conditioned positive and inhibitory stimuli

The activity of neurones of the visual and sensorimotor areas of the neocortex was simultaneously recorded in rabbits under the action of conditioned, inhibitory stimuli (CS, IS) and at simultaneous presentation of CS and the unconditioned stimulus (US) after trans-switching of the positive and inhibitory conditioned reflexes. Mean time of conjugated reactions of simultaneously recorded pairs of neurons is similar under the action of CS, combined action of CS and US and under IS. During the IS action as compared with CS, the phasic activity of some neurones in different areas increased, and due to this the similarity of reactions also increased; in other pairs of neurones the reactions weakened and the responses similarity decreased. The frequency of the appearance of intervals of the conjugated excitation after CS corresponds to 4.3 Hz; under combined action of CS and US it increases up to 5.9 Hz, and after IS--it decreases to 3.6 Hz. The order of coming into conjugated action of different pairs of neurones changes depending on the signal significance of the stimuli.     

Reproducibility and discriminability of brain patterns of semantic categories enhanced by congruent audiovisual stimuli

One of the central questions in cognitive neuroscience is the precise neural representation, or brain pattern, associated with a semantic category. In this study, we explored the influence of audiovisual stimuli on the brain patterns of concepts or semantic categories through a functional magnetic resonance imaging (fMRI) experiment. We used a pattern search method to extract brain patterns corresponding to two semantic categories: "old people" and "young people." These brain patterns were elicited by semantically congruent audiovisual, semantically incongruent audiovisual, unimodal visual, and unimodal auditory stimuli belonging to the two semantic categories. We calculated the reproducibility index, which measures the similarity of the patterns within the same category. We also decoded the semantic categories from these brain patterns. The decoding accuracy reflects the discriminability of the brain patterns between two categories. The results showed that both the reproducibility index of brain patterns and the decoding accuracy were significantly higher for semantically congruent audiovisual stimuli than for unimodal visual and unimodal auditory stimuli, while the semantically incongruent stimuli did not elicit brain patterns with significantly higher reproducibility index or decoding accuracy. Thus, the semantically congruent audiovisual stimuli enhanced the within-class reproducibility of brain patterns and the between-class discriminability of brain patterns, and facilitate neural representations of semantic categories or concepts. Furthermore, we analyzed the brain activity in superior temporal sulcus and middle temporal gyrus (STS/MTG). The strength of the fMRI signal and the reproducibility index were enhanced by the semantically congruent audiovisual stimuli. Our results support the use of the reproducibility index as a potential tool to supplement the fMRI signal amplitude for evaluating multimodal integration.     

Failure to condition evaluative and electrodermal responses to neutral stimuli by means of prepared cues

To test Gray's proposal (1979, 1982) that prepared cues (snakes, spiders) are unconditioned, innate fear stimuli, a classical conditioning procedure was carried out in which a neutral, conditioned stimulus (CS; slides of flowers, mushrooms or apples) was repeatedly followed by a prepared, unconditioned stimulus (US; slides of snakes or spiders). Dependent variables were subjective evaluation of, and skin conductance responses to the CS slides, while respiration was used as a control variable. In one group of subjects (n = 12), skin conductance was recorded from the left hand, whereas in a second group (n = 11) it was recorded from the right hand. No evidence of skin conductance response - or of evaluative conditioning to the neutral CS as a result of its being paired with the prepared US was found. Thus, the results lend no support to Gray's proposal. No differences in skin conductance responses as a function of left versus right hand recording were found.     

Classical conditioning of human systolic pressure: replication and extension using three stimulus durations

Recent efforts have demonstrated classical conditioning of human systolic pressure (De Leon, 1972). The present research attempted a replication with longer sessions and to maximize the CS+, CS- differentiation by varying CS+ durations. Student volunteers (N = 64) underwent four, 50 minute sessions, three conditioning and one extinction, distributed over two weeks. Shock (UCS) occurred intermittently in light-on (CS+) and never in light-off (CS-). Results closely replicated the earlier work, revealing a characteristic UCR, a significant CS+, CS- differential and, conditioned elevations failed to adapt within and across sessions. The pressure differential was inversely related to CS+ duration. Clarification of conditioning influences requires follow-up research on these clients outside of the laboratory. Nevertheless, these studies provide firm experimental evidence for implicating stimulus variables in the origins of certain hypertensive states.     

Blocked and test-stimulus exposure effects in perceptual learning re-examined

Three experiments re-examined the effects of blocked or alternated exposure to the conditioning and test stimuli and the effect of simple exposure to the test stimulus, on stimulus generalization. In all experiments rats received conditioning where a compound flavor, AX, was paired with LiCl-induced illness. All rats were tested for generalization with another flavor, BX. In Experiment 1, rats that received alternating exposure to the two flavor compounds, AX and BX, prior to conditioning showed less generalization to BX than rats that received no exposure. Exposure to BX or AX alone was also somewhat effective in reducing generalization. In Experiment 2 blocked exposure to AX and BX prior to conditioning was effective in reducing generalization, as was alternated exposure, and extended exposure to BX was more effective than the other procedures. In Experiment 3, exposure to X alone prior to conditioning produced generalization equal to that produced by alternated or blocked exposure and replicated the effect of extended exposure to BX found in the previous experiment. The relevance of the results to the theories proposed by McLaren and Macintosh [Anim. Learn. Behav. 28 (2000) 211] and Hall [Q. J. Exp. Psychol. B 56 (2003) 43] is discussed.     

Mineralization of 2-chloro- and 2,5-dichlorobiphenyl by Pseudomonas sp. strain UCR2

Pseudomonas sp. strain UCR2 was isolated from a multi-chemostat mating experiment between a chlorobenzoate-degrader, Pseudomonas aeruginosa strain JB2, and a chlorobiphenyl-degrader, Arthrobacter sp. strain B1Barc. Strain UCR2 differed from either of the parental organisms in that it grew on both 2-chloro- and 2,5-dichlorobiphenyl with concomitant release of chloride. Phenotypic typing by the Biolog system indicated that strain UCR2 shared greater similarity with strain JB2 (88%) than strain B1Barc (3%). In DNA:DNA hybridization experiments, genomic DNA from strain UCR2 hybridized with both strain JB2 and strain B1Barc, with the former pairing yielding a much stronger signal than the latter. In contrast, no hybridization whatsoever was observed when the parental organisms strains JB2 and B1Barc were probed against each other.     

Altered Inhibitory Control and Increased Sensitivity to Cross-Modal Interference in Tinnitus during Auditory and Visual Tasks

Tinnitus is the perception of sound in the absence of external stimulus. Currently, the pathophysiology of tinnitus is not fully understood, but recent studies indicate that alterations in the brain involve non-auditory areas, including the prefrontal cortex. In experiment 1, we used a go/no-go paradigm to evaluate the target detection speed and the inhibitory control in tinnitus participants (TP) and control subjects (CS), both in unimodal and bimodal conditions in the auditory and visual modalities. We also tested whether the sound frequency used for target and distractors affected the performance. We observed that TP were slower and made more false alarms than CS in all unimodal auditory conditions. TP were also slower than CS in the bimodal conditions. In addition, when comparing the response times in bimodal and auditory unimodal conditions, the expected gain in bimodal conditions was present in CS, but not in TP when tinnitus-matched frequency sounds were used as targets. In experiment 2, we tested the sensitivity to cross-modal interference in TP during auditory and visual go/no-go tasks where each stimulus was preceded by an irrelevant pre-stimulus in the untested modality (e.g. high frequency auditory pre-stimulus in visual no/no-go condition). We observed that TP had longer response times than CS and made more false alarms in all conditions. In addition, the highest false alarm rate occurred in TP when tinnitus-matched/high frequency sounds were used as pre-stimulus. We conclude that the inhibitory control is altered in TP and that TP are abnormally sensitive to cross-modal interference, reflecting difficulties to ignore irrelevant stimuli. The fact that the strongest interference effect was caused by tinnitus-like auditory stimulation is consistent with the hypothesis according to which such stimulations generate emotional responses that affect cognitive processing in TP. We postulate that executive functions deficits play a key-role in the perception and maintenance of tinnitus.     

Spatial serial conditioning maintained with minimal temporal contingency

Two experiments used a spatial serial conditioning paradigm to assess the effectiveness of spatially informative conditioned stimuli in eliciting tracking behavior in pigeons. The experimental paradigm consisted of the simultaneous presentation of 2 key lights (CS2 and CTRL), followed by another key light (CS1), followed by food (the unconditioned stimulus or US). CS2 and CTRL were presented in 2 of 3 possible locations, randomly assigned; CS1 was always presented in the same location as CS2. CS2 was designed to signal the spatial, but not the temporal locus of CS1; CS1 signaled the temporal locus of the US. In experiment 1, differential pecking on CS2 was observed even when CS2 was present throughout the interval between consecutive presentations of CS1, but only in a minority of pigeons; prevalence of differential pecking was enhanced when CS2 duration was halved. A control condition verified that pecking on CS2 was not due to temporal proximity between CS2 and US. Experiment 2 demonstrated the reversibility of spatial conditioning between CS2 and CTRL. Asymptotic performance never involved tracking CTRL more than CS2 for any of 16 pigeons. It is inferred that pigeons learned the spatial association between CS2 and CS1, and that temporal contingency facilitated its expression as tracking behavior.     

UCR1 and UCR2 domains unique to the cAMP-specific phosphodiesterase family form a discrete module via electrostatic interactions

The cAMP-specific phosphodiesterases (PDE4) enzymes contain unique "signature" regions of amino acid sequence, called upstream conserved regions 1 and 2 (UCR1 and UCR2). UCR1 and UCR2 are located between the extreme amino-terminal region and the catalytic region of the PDE4 enzymes. The UCR1 of the PDE4D3 isoform was used as a "bait" in a two-hybrid screen, which identified a PDE4D cDNA clone containing UCR2 and the catalytic region but not UCR1. Two-hybrid and "pull down" analysis of constructs incorporating various regions of the PDE4D3 cDNA demonstrated that the carboxyl-terminal region of UCR1 interacted specifically with the amino-terminal region of UCR2. The interaction was blocked by mutations of two positively charged amino acids (Arg-98 and Arg-101 to alanine) located within an otherwise largely hydrophobic region of UCR1. Mutation of three negatively charged amino acids in UCR2 (Glu-146, Glu-147, and Asp-149, all to alanine) also blocked the interaction. The phosphorylation of UCR1 by cAMP-dependent protein kinase (PKA) in vitro attenuated the ability of UCR1 to interact with UCR2. Mutation of the PKA substrate site in UCR1 (Ser-54) to aspartic acid, which mimics the activation of PDE4D3 by PKA, profoundly reduced the interaction between UCR1 and UCR2. Our data are consistent with a model in which UCR1 and UCR2 act as independent domains whose interaction is determined by electrostatic interactions and which may be disrupted by PKA phosphorylation. We suggest that the UCR1 and UCR2 domains may form a module that interacts with and regulates the PDE4 catalytic region.     

Conditioned augmentation of natural killer cell activity. Independence from nociceptive effects and dependence on interferon-beta

Injection of mice with 20 micrograms polyinosinic: polycytidylic acid (Poly I:C) after exposure to camphor odor results in a conditioned augmentation of natural killer cell (NK) activity. In this study, we show that the conditioned response is not the result of nociceptive stimulation and that interferon-beta (IFN), but not IFN-alpha can replace Poly I:C as the unconditioned stimulus (US). Two conditioned stimuli (CS) were used with equivalent results. A combination CS consisting of a novel taste (saccharin) and a 125 mg/kg injection of LiCl that induces gastric upset was paired with a Poly I:C or IFN-beta (1 X 10(4) IU) injection. This resulted in an augmentation of NK activity when the conditioned animals were reexposed to the saccharin-LiCl CS. In addition, an identical conditioned response was elicited when a camphor odor CS was paired with either of these US. To test whether the conditioned response might be an artifact not detected by our controls, a mock conditioning experiment was performed, which assessed the differential effect of multiple exposures to the saccharin-LiCl CS without a CS/US pairing. The mock conditioned group was significantly suppressed relative to saline treated controls, whereas the mock nonconditioned group and the mock conditioned group that was not reexposed to the CS after conditioning did not show significant suppression. This indicates that the augmentation observed in the conditioned group after CS/US pairing was not the result of exposure to the CS itself. Small doses of Poly I:C (5 micrograms or 2.5 micrograms) given on days 3 and 5 (or on day 5 only) to boost NK activity had the effect of increasing the magnitude of the conditioned response measured on day 6. In addition, an identical conditioned response was observed when the interval between the CS/US pairing and the later CS exposures was changed, which places the test for the conditioned response either on day 6 (CS given on days 3 and 5) or day 10 (CS given on days 7 and 9). These results show that the observed conditioned enhancement of NK activity in conditioned animals is not caused by any nociceptive properties of the CS itself and is dependent on the IFN-beta produced after Poly I:C injection in the conditioned paradigm.     

Dissection of the immediate early response of myeloid leukemia cells to terminal differentiation and growth inhibitory stimuli

To better understand the immediate early genetic response of myeloid cells to terminal differentiation and growth inhibitory stimuli, complementary DNA clones of myeloid differentiation primary response (MyD) genes have recently been isolated. In this study, a set of known (junB, c-jun, ICAM-1, H1(0), and H3.3 histone variants) and novel (MyD88, MyD116) MyD genes were used as immediate early molecular markers to further dissect the primary genetic response of myeloid cells to various differentiation and growth inhibitory stimuli. Expression of all of these MyD genes was highly induced in autonomously replicating differentiation inducible M1D+ myeloblasts following induction of terminal differentiation and growth inhibition by interleukin 6. Expression of all MyD genes except MyD88 was induced upon inhibition of M1D+ cell growth and induction of early, but not late, differentiation markers by interleukin 1 and lipopolysaccharide. In sharp contrast, only expression of H1(0) and H3.3 histone variants was increased following inhibition of M1D+ cell growth by interferon beta or gamma, which did not induce any differentiation associated properties. No increase in the expression of any of these MyD genes was seen in a clone of WEHI-3B D- myelomonocytic cells following stimulation with interleukin 6, which neither induced it for differentiation nor inhibited its growth. 12-O-Tetradecanoylphorbol-13-acetate, known to be a potent inducer of jun expression in many cell types, failed to induce high or stable expression of junB and c-jun in M1D+ cells, where it did not induce differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)