Ventral lateral geniculate input to the medial pons is necessary for visual eyeblink conditioning in rats

The conditioned stimulus (CS) pathway that is necessary for visual delay eyeblink conditioning was investigated in the current study. Rats were initially given eyeblink conditioning with stimulation of the ventral nucleus of the lateral geniculate (LGNv) as the CS followed by conditioning with light and tone CSs in separate training phases. Muscimol was infused into the medial pontine nuclei (MPN) after each training phase to examine conditioned response (CR) retention to each CS. The spread of muscimol infusions targeting the MPN was examined with fluorescent muscimol. Muscimol infusions into the MPN resulted in a severe impairment in retention of CRs with the LGNv stimulation and light CSs. A less severe impairment was observed with the tone CS. The results suggest that CS information from the LGNv and light CSs is relayed to the cerebellum through the MPN. Retrograde tracing with fluoro-gold (FG) showed that the LGNv and nucleus of the optic tract have ipsilateral projections to the MPN. Unilateral inputs to the MPN from the LGNv and nucleus of the optic tract may be part of the visual CS pathway that is necessary for visual eyeblink conditioning.The neural substrates of associative motor learning have been studied extensively using eyeblink conditioning (Christian and Thompson 2003; Thompson 2005). Eyeblink conditioning is typically established by pairing a tone or light conditioned stimulus (CS) with an unconditioned stimulus (US) that elicits the eyeblink reflex. An eyeblink conditioned response (CR) emerges over the course of paired training, and the peak of eyelid closure occurs at the onset time of the US. Results from experiments using temporary lesions of the cerebellar deep nuclei or cerebellar cortex indicate that the anterior interpositus nucleus and cerebellar cortex are necessary for acquisition, expression, and extinction of eyeblink conditioning (Krupa et al. 1993; Hardiman et al. 1996; Krupa and Thompson 1997; Garcia and Mauk 1998; Medina et al. 2001; Bao et al. 2002; Freeman et al. 2005a). Blocking cerebellar output with inactivation of the superior cerebellar peduncle, red nucleus, or brainstem motor nuclei selectively blocks CR expression but not acquisition, providing further evidence that learning occurs in the cerebellum (Chapman et al. 1990; Krupa et al. 1993, 1996; Krupa and Thompson 1995).Sensory stimuli from every modality are sent to the pontine nuclei (PN), which receive projections from the lower brainstem, thalamus, and cerebral cortex (Glickstein et al. 1980; Brodal 1981; Mihailoff et al. 1989; Schmahmann and Pandya 1989; Wells et al. 1989; Knowlton et al. 1993; Campolattaro et al. 2007). Neurons in the PN project CS information to the cerebellum via mossy fibers in the middle cerebellar peduncle that synapse on granule cells in the cerebellar cortex and on neurons in the interpositus nucleus (Bloedel and Courville 1981; Brodal 1981; Steinmetz and Sengelaub 1992; Mihailoff 1993). Lesions of the middle cerebellar peduncle impair eyeblink conditioning with auditory, somatosensory, and visual CSs (Lewis et al. 1987). Bilateral electrolytic lesions of the dorsolateral and lateral pontine nuclei (LPN) block retention of CRs to an auditory CS but have no effect on light-elicited CRs (Steinmetz et al. 1987). Inactivation of the contralateral LPN blocks CRs to a tone CS but not to lateral reticular nucleus stimulation in rabbits (Bao et al. 2000). Moreover, stimulation of the LPN or middle cerebellar peduncle is a sufficient CS for eyeblink conditioning (Steinmetz et al. 1986, 1987; Tracy et al. 1998; Bao et al. 2000; Freeman and Rabinak 2004; Freeman et al. 2005b; Campolattaro and Freeman 2008). The findings from the lesion, inactivation, and stimulation studies provide evidence that the PN is the proximal part of the CS pathway for cerebellar learning. These studies also indicate that the LPN is the primary source of auditory CS input to the cerebellum.Only a few studies have examined the visual CS pathway necessary for eyeblink conditioning. The dorsal and ventral divisions of the lateral geniculate nucleus of the thalamus (LGNd, LGNv), pretectal nuclei, visual cortex (VCTX), and superior colliculus (SC) comprise a hypothesized parallel visual CS pathway for eyeblink conditioning (Koutalidis et al. 1988). Combined lesions of all of these visual areas completely block acquisition, lesions of two visual areas produce a partial impairment, and lesions in one visual area do not impair CR acquisition (Koutalidis et al. 1988). Stimulation of the VCTX, SC, and LGNv support eyeblink conditioning, and each of these structures has a direct unilateral projection to the PN that could be important for eyeblink conditioning (Halverson et al. 2009). The lesion and stimulation studies provide evidence that structures in the hypothesized visual CS pathway are independently capable of supporting conditioning. An important aspect of the visual CS pathway proposed in the Koutalidis et al. (1988) study is distributed projections of each visual area to different regions of the PN. The important projections were hypothesized to be from the VCTX to the rostral portion of the PN, from both the SC and pretectal nuclei to the dorsolateral PN, and the LGNv projection to the medial pontine nuclei (MPN) (Koutalidis et al. 1988). Lesions of the VCTX were substituted for LGN lesions in the Koutalidis et al. (1988) study due to technical problems with animal survival. The LGNv projection to the MPN was therefore not examined in their combined lesion group. Stimulation of the anterior pretectal nucleus is not a sufficient CS to support eyeblink conditioning (Campolattaro et al. 2007). The direct PN projection from the VCTX is not necessary for CR retention to a light CS, as lesions do not prevent eyeblink conditioning to a light CS in dogs or monkeys (Hilgard and Marquis 1935, 1936). Moreover, lesions of the entire cerebral cortex do not prevent acquisition or retention of delay eyeblink conditioning to a tone or light CS in rabbits (Oakley and Russell 1972, 1977). The LGNv and SC, therefore, are likely sources of visual input to the PN that is necessary for eyeblink conditioning.The current experiment investigated whether information from the LGNv and a visual CS (light) share similar inputs into the MPN and whether those inputs are different from an auditory CS. The visual projections to the MPN were also investigated with the retrograde tracer fluoro-gold (FG) to identify structures that may be involved with the relay of CS information during eyeblink conditioning. In the conditioning experiment, rats received three phases of training, with each phase consisting of three acquisition sessions followed by a muscimol infusion into the MPN, and then a saline recovery session. Each rat received unilateral stimulation of the LGNv (contralateral to the trained eye) during phase 1 of training followed by either a tone or light CS in phases 2 and 3 (order of stimulus presentation was counterbalanced). One group received LGNv stimulation in phase 1 followed by a light CS in phase 2, and a tone CS in phase 3 (SLT). The other group received the tone CS in phase 2, and light CS in phase 3 (STL).     

The Role of Women's Relationships With Their Partners in Their Adjustment Following Prenatal Genetic Testing1

This study explored how aspects of the couple relationship contributed to the adjustment of 95 women who underwent prenatal diagnostic (PND) testing because of advanced maternal age (AMA). Participants completed self‐report measures prior to genetic counseling (T1), during the waiting period for PND test results (T2), and after normal results were received (T3). At T2, distress was predicted by the degree to which women approached the PND decision jointly with their partners, and marital adjustment was predicted by women's satisfaction with the support received from their partners. Marital adjustment at T3 was predicted by earlier levels of partner agreement about PND‐related issues. Results suggest that the couple relationship has the potential to facilitate or hinder women's experience of PND testing.     

Medial auditory thalamic stimulation as a conditioned stimulus for eyeblink conditioning in rats

The neural pathways that convey conditioned stimulus (CS) information to the cerebellum during eyeblink conditioning have not been fully delineated. It is well established that pontine mossy fiber inputs to the cerebellum convey CS-related stimulation for different sensory modalities (e.g., auditory, visual, tactile). Less is known about the sources of sensory input to the pons that are important for eyeblink conditioning. The first experiment of the current study was designed to determine whether electrical stimulation of the medial auditory thalamic nuclei is a sufficient CS for establishing eyeblink conditioning in rats. The second experiment used anterograde and retrograde tract tracing techniques to assess neuroanatomical connections between the medial auditory thalamus and pontine nuclei. Stimulation of the medial auditory thalamus was a very effective CS for eyeblink conditioning in rats, and the medial auditory thalamus has direct ipsilateral projections to the pontine nuclei. The results suggest that the medial auditory thalamic nuclei and their projections to the pontine nuclei are components of the auditory CS pathway in eyeblink conditioning.     

Early identification of mental health problems in schools: The status of instrumentation

When embedded within a continuum of mental health services including both prevention and treatment, school-based mental health identification programs can promote improved academic and mental health functioning among students. This article describes the scientific status of assessment instrumentation that may be used for early mental health identification in schools. Currently available instruments are described in terms of their ability to accurately detect youth with mental health problems. Implications for selecting mental health screening and assessment instruments and integrating them into schools are discussed. Finally, a range of approaches to early identification in schools as well as some of the broader ethical and practical issues related to the integration of these strategies into a school-wide continuum of services are presented.     

Stimulation of the lateral geniculate,superior colliculus,or visual cortex is sufficient for eyeblink conditioning in rats

The role of the cerebellum in eyeblink conditioning is well established. Less work has been done to identify the necessary conditioned stimulus (CS) pathways that project sensory information to the cerebellum. A possible visual CS pathway has been hypothesized that consists of parallel inputs to the pontine nuclei from the lateral geniculate nucleus (LGN), superior colliculus (SC), pretectal nuclei, and visual cortex (VCTX) as reported by Koutalidis and colleagues in an earlier paper. The following experiments examined whether electrical stimulation of neural structures in the putative visual CS pathway can serve as a sufficient CS for eyeblink conditioning in rats. Unilateral stimulation of the ventral LGN (Experiment 1), SC (Experiment 2), or VCTX (Experiment 3) was used as a CS paired with a periorbital shock unconditioned stimulus. Stimulation was delivered to the hemisphere contralateral to the conditioned eye. Rats in all experiments were given five 100-trial sessions of paired or unpaired eyeblink conditioning with the stimulation CS followed by three paired sessions with a light CS. Stimulation of each visual area when paired with the unconditioned stimulus supported acquisition of eyeblink conditioned responses (CRs) and substantial savings when switched to a light CS. The results provide evidence for a unilateral parallel visual CS pathway for eyeblink conditioning that includes the LGN, SC, and VCTX inputs to the pontine nuclei.Pavlovian eyeblink (eyelid closure and nictitating membrane movement) conditioning is established by pairing a conditioned stimulus (CS), usually a tone or light, with an unconditioned stimulus (US) that elicits the eyeblink reflex. The eyeblink conditioned response (CR) emerges over the course of paired training, occurs during the CS, and precedes the US (Gormezano et al. 1962; Schneiderman et al. 1962). Neurobiological investigations of Pavlovian eyeblink conditioning have primarily focused on the cerebellum, which is the site of memory formation and storage (Thompson 2005). The anterior interpositus nucleus is necessary for acquisition and retention of the eyeblink CR (Lavond et al. 1985; Krupa and Thompson 1997; Freeman Jr. et al. 2005; Thompson 2005; Ohyama et al. 2006). Lobule HVI and the anterior lobe of the cerebellar cortex (lobules I–V) contribute to acquisition, retention, and timing of the CR (McCormick and Thompson 1984; Perrett et al. 1993; Perrett and Mauk 1995; Attwell et al. 1999, 2001; Medina et al. 2000; Nolan and Freeman Jr. 2005; Nolan and Freeman 2006). The brainstem nuclei that comprise the proximal ends of the CS and US input pathways to the cerebellum have also been identified.The pontine nuclei (PN) and inferior olive (IO) receive CS and US information, respectively, and are the primary sensory relays into the interpositus nucleus and cerebellar cortex (Thompson 2005). Conditioned stimulus information converges in the PN, which receives projections from lower brainstem, thalamus, and cerebral cortex (Glickstein et al. 1980; Brodal 1981; Schmahmann and Pandya 1989; Knowlton et al. 1993; Campolattaro et al. 2007). The lateral pontine nuclei (LPN) are the sources of auditory CS information projected into the cerebellum. Lesions of the LPN block CR retention to a tone CS, but have no effect on CRs to a light CS (Steinmetz et al. 1987). Thus, CS inputs from different sensory modalities may be segregated at the level of the PN. Neurons in the PN project CS information into the contralateral cerebellum via mossy fibers in the middle cerebellar peduncle that synapse primarily on granule cells in the cerebellar cortex and on neurons in the deep nuclei (Bloedel and Courville 1981; Brodal 1981; Steinmetz and Sengelaub 1992). Stimulation of the PN acts as a supernormal CS supporting faster CR acquisition than conditioning with peripheral stimuli (Steinmetz et al. 1986, 1989; Rosen et al. 1989; Steinmetz 1990; Tracy et al. 1998; Freeman Jr. and Rabinak 2004). The primary focus of these experiments was to investigate the most proximal components of the CS pathway in eyeblink conditioning. There has been less emphasis on identifying the critical CS pathways that project information to the PN.Recent studies using lesions, inactivation, stimulation, and neural tract tracing have provided evidence that the auditory CS pathway that is necessary for acquisition and retention of eyeblink conditioning is comprised of converging inputs to the medial auditory thalamic nuclei (MATN), and a direct ipsilateral projection from the MATN to the PN (Halverson and Freeman 2006; Campolattaro et al. 2007; Freeman et al. 2007; Halverson et al. 2008). Unilateral lesions of the MATN, contralateral to the conditioned eye, block acquisition of eyeblink CRs to a tone CS but have no effect on conditioning with a light CS (Halverson and Freeman 2006). Inactivation of the MATN with muscimol blocks acquisition and retention of CRs to an auditory CS, and decreases metabolic activity in the PN (Halverson et al. 2008). The MATN has a direct projection to the PN and stimulation of the MATN supports rapid CR acquisition (Campolattaro et al. 2007). Our current model of the auditory CS pathway consists of converging inputs to the MATN, and direct unilateral thalamic input to the PN (Halverson et al. 2008).Less work has been done to identify the visual CS pathway necessary for eyeblink conditioning. A possible parallel visual CS pathway has been hypothesized, which includes parallel inputs to different areas of the PN from the lateral geniculate nucleus (LGN), superior colliculus (SC), visual cortex (VCTX), and pretectal nuclei (Koutalidis et al. 1988). In the Koutalidis et al. study, lesions of the LGN, SC, VCTX, or pretectal nuclei alone had only a partial effect on CR acquisition with a light CS. Lesions of any two of these structures together produced a more severe impairment on acquisition and combined lesions of all of these areas completely blocked CR acquisition to a light CS (Koutalidis et al. 1988). Each visual area investigated in the Koutalidis et al. study has a direct projection to the PN that could be important for eyeblink conditioning. The ventral LGN projects to the medial, and to a lesser extent, the lateral PN (Graybiel 1974; Wells et al. 1989). The superficial, intermediate, and deep layers of SC send projections to both the dorsomedial and dorsolateral PN (Redgrave et al. 1987; Wells et al. 1989). The VCTX has a direct projection to the rostral and lateral portions of the PN (Glickstein et al. 1972; Baker et al. 1976; Mower et al. 1980; Wells et al. 1989). The pretectal nuclei also have a direct projection to both the medial and lateral PN (Weber and Harting 1980; Wells et al. 1989). However, stimulation of the anterior pretectal nucleus is not an effective CS for eyeblink conditioning (Campolattaro et al. 2007). The failure to establish conditioning with stimulation of the anterior pretectal nucleus as a CS suggests that there may be differences in the efficacy of the various visual inputs to the PN for cerebellar learning. The following experiments investigated the sufficiency of stimulation of the LGN, SC, or primary VCTX as a CS for eyeblink conditioning in rats.     

Body image and explicit and implicit anti-fat attitudes: the mediating role of physical appearance comparisons

Prejudice against overweight people is rife. However, there is a paucity of research on the underlying reasons for it. In two studies the relationship between body image, the tendency to make physical appearance-related comparisons (PACS), and both explicit and implicit anti-fat attitudes was examined. In Study 1 (n = 227) people with a high tendency to make physical appearance-related comparisons (high PACS scorers) reported lower self-appearance evaluation, but higher appearance orientation and explicit anti-fat attitudes. The PACS fully mediated the relationship between appearance orientation and explicit anti-fat attitudes. Study 2 (n = 134) found that the PACS also mediated the relationship between appearance orientation and implicit anti-fat attitudes. Thus, individual differences in factors such as body image and the tendency to make appearance-related comparisons, appear to play a central role in both explicit and implicit anti-fat attitudes.     

The Coming-Out Process and Its Adaptational and Health-Related Associations Among Gay, Lesbian, and Bisexual Youths: Stipulation and Exploration of a Model

A model is proposed and explored that links the coming-out process to the psychological functioning (i.e., self-esteem and distress) and sexual behaviors of gay, lesbian, and bisexual youths recruited from gay-focused community-based and college organizations in New York City. The coming-out process is multidimensional, consisting, as defined here, of involvement in gay/lesbian activities, attitudes toward homosexuality, comfort with homosexuality, self-disclosure of sexual identity to others, and sexual identity. The coming-out dimensions were related to self-esteem, distress, and unprotected sexual behaviors. In addition, the relations between the coming-out dimensions and unprotected sexual behaviors were explained by psychological functioning. In particular, limited involvement in gay/lesbian activities was associated with more unprotected sex. Negative attitudes toward homosexuality were related directly to more unprotected sex, and they were related indirectly to more unprotected sex by means of increasing emotional distress. These and other findings have implications for designing preventive interventions to increase the youths' psychological functioning and reduce their unprotected sexual behaviors.     

Long-term memory in adulthood: An examination of the development of storage and retrieval processes at acquisition and retention

Although it is generally acknowledged that decrements in long-term memory play an important role in the decline of everyday cognitive functioning in adulthood, problems have arisen in localizing the source of these memory deficits. In this article we address three of the methodological and measurement issues that have led to difficulties in interpreting research on adulthood developmental differences in acquisition and long-term retention. Specifically, these issues are stages-of-learning confounds, failures to separate storage and retrieval processes, and failures to separate forgetting from other factors that influence long-term retention tests. A general framework is presented in which each of these problems is dealt with. This model is subsequently applied to an experiment that examined the acquisition and long-term retention of pictures and words in associative memory in both young and old adults. The major findings were that (a) the picture-word manipulation had asymmetrical effects on acquisition and retention, (b) these asymmetries were different for the young and old adults, and (c) the locus (storage/retrieval) of age differences was different at acquisition than at retention. These results strongly suggest that the rules governing acquisition and forgetting are different, not only within age groups, but also across developmental levels in adulthood. More importantly, because the locus of developmental differences was different for acquisition and forgetting, it may be that different mechanisms underly the processing deficits experienced by the elderly when acquiring information than when trying to retain that information over extended periods of time.     

Factors associated with erection in adolescent sex offenders

A majority of adult child molesters report that their deviant interest began prior to the age of 18. This illustrates the need to evaluate adolescents who have molested children. Since self-report of deviant interest is rare in adolescent offenders, psychophysiologic assessment is necessary to help to determine the extent for a deviant interest pattern. The current study was designed to determine what factors are associated with erectile responding to age-inappropriate stimuli in an adolescent sex offender population. Factors studied were (a) admit/deny, (b) history of physical abuse, (c) history of sexual abuse, (d) history of nonsex arrests, and (e) incest/nonincest. The dependent variables were two pedophile indices, a relative measure of deviant to nondeviant arousal. Results indicated that history of sexual abuse was associated with more deviant erectile responding in those adolescents who had molested young boys. The possibility of adolescents modeling their own victimization is discussed.