Individual differences in cardiac and EMG activity after smoking

Motivational State and Personality in Relation to Emotion, Stress, and HRV Responses to Aerobic Exercise

Abstract. This study examined emotion, stress, and performance during aerobic exercise performed in the telic and paratelic states, in relation to telic and paratelic dominance. The study tested the misfit effect and is the first to examine heart rate variability (HRV) responses to exercise in relation to both personality and motivational state. Based on their Paratelic Dominance Scale scores, participants identified as telic dominant (TD) and paratelic dominant (PD) completed ramp tests following telic and paratelic state manipulations (repeated measures). In each condition, participants watched “serious” (telic) or “playful” (paratelic) videos for 10 min, then performed a ramp test on a cycle ergometer while continuing to watch the videos throughout the entire protocol. Motivational state (telic/paratelic), HRV, emotion, and stress levels were measured at baseline, pre, post, and 15 min post-ramp test. Time to exhaustion was measured as an index of performance. Limited support was obtained for the misfit effect as interactions between state and dominance were not revealed for any of the variables with the exception of low frequent (LF) and the low frequent/high frequent ratio (LF/HF % normalized), which can be interpreted as indicating that both groups were more relaxed in their preferred state condition. Regardless, findings offer useful insight into methodological considerations for similar studies, such as consideration of the moderating effects of exercise characteristics. Our findings also confirm a number of reversal theory ( Apter, 1982 ) proposals including the concept of dominance as an individual difference factor, with varying characteristics of different dominances, based on physiological response variables. We recommend continued research into the misfit effect with larger samples, and designs that accommodate the methodological considerations raised by the present results.

Individual variation in the expression profiles of nicotinic receptors in the olfactory bulb and trigeminal ganglion and identification of alpha2, alpha6, alpha9, and beta3 transcripts

Nicotine evokes dose-dependent and often variable chemosensory responses in animals and humans. Earlier observations that nicotine binds to some nicotinic acetylcholine receptor (nAChR) subtypes in the olfactory bulb (OB) and trigeminal ganglion (TG) led us to investigate the complete nAChR expression profile in each tissue and to determine whether inter-individual differences exist in male and female rats. Total RNA was extracted from individual samples of dissected OB and TG and analyzed by a sensitive reverse transcription-polymerase chain reaction (RT-PCR) assay to determine the messenger RNA profiles of ten transcripts encoded by the alpha2, alpha3, alpha4, alpha5, alpha6, alpha7, alpha9, beta2, beta3, and beta4 nAChR genes. We found that (a) in the OB, all animals expressed alpha2, alpha3, alpha4, alpha5, alpha7, beta2, and beta4 subunit mRNAs, whereas alpha6, beta3, and alpha9 transcripts were expressed in only 17, 28, and 33% of the animals, respectively, and (b) in the TG, all animals expressed alpha2, alpha3, alpha6, alpha7, beta2, and beta4 subunit mRNAs, whereas alpha9, beta3, alpha4, and alpha5 transcripts were expressed in 4, 38, 88, and 92% of the animals, respectively. These results also identified new subunits that are expressed in each tissue (alpha2, alpha6, alpha9, and beta3) and demonstrated that individual rats may have different tissue-specific expression profiles for alpha4, alpha5, alpha6, alpha9, and beta3 transcripts. Such variations are likely to be reflected in the composition of functional receptor subtypes in the rat OB and TG that have different activation and desensitization characteristics to acetylcholine and nicotine.