Recollection is impaired,but familiarity remains intact in rats with lesions of the fornix

It has been argued that a neural system including the hippocampus, fornix, mamillary bodies, and anterior thalamus is specifically involved in recollection, but not in familiarity based memory processes. Here we test this hypothesis using a task of episodic‐like memory within an E‐shaped maze. Animals seek out a preferred object (what) in a particular location (where) that is unique to a particular context (which occasion). As objects are hidden from view at the point of decision making, the animals can only base their decision on recall of their previous episode in the E‐shaped maze. In contrast, once a decision has been made animals are free to explore both objects and display an object preference when objects are visible to the animal and decisions can be made on the basis of familiarity. Animals with fornix lesions are impaired at recalling a past event. However, the same animals on the same trials show no such impairment in a judgement of familiarity. We therefore demonstrate that recall is dependent upon the fornix, while familiarity based memory is not. © 2009 Wiley‐Liss, Inc.     

Relationship between Hippocampal Atrophy and Cognitive Dysfunction in Early Alzheimer-type Dementia

Background: We assessed the relationship between early cognitive dysfunction and morphologic changes in the brain, especially hippocampal atrophy, on MR images in Alzheimer‐type dementia (AID) patients to establish a technique for making an early clinical diagnosis of AID. Methods: The subjects of this study were 82 individuals who visited Kawase Neurology Clinic. They consisted of 41 ATD patients and 41 elderly individuals without dementia who visited the clinic for a neurological checkup or because of vertigo or numbness as age‐matched controls. As an index for hippocampal atrophy, the hippocampal‐intracranial ratio (HIR) was calculated. Discriminant analysis was performed using HIR results and the correct answer rate for recall and calculation items in Mini‐Mental State Examination (MMSE). Results: The mean ratio was significantly lower in the ATD patients than in the controls. This supports our previous results. The results of discriminant analysis with Mahalanobis generalized distance in the 41 controls and 22 ATD patients who scored 15 or higher. The sensitivity and specificity of HIR combined with the correct answer rate for recall and calculation items in MMSE were 95.5% and 95.1%, respectively, with an overall accuracy of 95.2%. Conclusion: HIR combined with the correct answer rate for recall and calculation items in MMSE allows for an early diagnosis of ATD.     

Triazolam premedication

A randomised, double blind study, of 58 female patients undergoing laparoscopic investigation was carried out to compare triazolam 0.25 mg, lorazepam 2 mg, or placebo as oral premedication. Each patient was assessed by only one of the authors both pre- and postoperatively with regard to anxiolysis, sedation and rapidity of recovery. Triazolam and lorazepam were each associated with a significant reduction in anxiety compared to the initial assessment, whereas placebo had no anxiolytic effect. Sixty minutes after premedication, patients who had received triazolam were significantly more sleepy than patients given placebo or lorazepam. Two hours after the operation, the patients who had had triazolam or lorazepam were significantly more sleepy than those who received placebo. However, at 6 hours postoperatively there was no difference between triazolam and placebo, whilst those who had been given lorazepam were still significantly more sleepy than those given placebo. Triazolam appears to offer advantages over either lorazepam or placebo in patients who require rapid recovery, sedation and reduction in pre-operative anxiety.     

Fatal Outcome in a Pacemaker-Dependent Patient

The recent advisory of Medtronic Sprint Fidelis leads has resulted in significant controversy over proper management of patients. The current manufacture's guidelines recommend programming specific device alerts with close follow-up and implantable cardioverter-defibrillator lead replacement in patients with evidence of breach in lead integrity. Recently, several studies have identified significant limitations in this method of surveillance. We report the case of a pacemaker-dependent patient with an ischemic cardiomyopathy, who presented with cardiac arrest and evidence of fracture of the pace/sense portion of a Sprint Fidelis lead during postmortem interrogation. Likely mechanisms leading to his ultimate demise are discussed.     

Effects of alcohol on recall of social interactions

This experiment used a balanced placebo design and investigated the effects of alcohol, expectancy, and sex of subject on normal drinkers' recall of social interactions. In a 2 ×2 ×2 factorial design, 48 males and 48 females were (a) administered an alcoholic (.7 g/kg) or a nonalcoholic beverage, and (b) instructed that they had received an alcoholic or a nonalcoholic beverage. Subjects then heard four audiotaped dyadic interactions, and their recall for factual aspects of each interaction was assessed. A significant Beverage ×Instruction interaction showed that alcohol consumption impaired subjects' recall under the told nonalcohol instructional condition, and that the best recall scores were attained by subjects whose beverage and instruction conditions were congruent. Females showed better recall than males. With qualifications, these data support the use of an information-processing approach to investigate cognitive functions relevant to the social behavioral effects of alcohol.     

Recalling in a state of natural or experimental depression

In three experiments we attempted to extend the cognitive-effort account of depressive deficits in memory to naturally depressed college students. This account maintains that depression reduces attentional resources, thereby impairing performance on demanding tasks, and has received support through experimental inductions of depressed moods. Nondepressed, naturally depressed, and (in Experiment 2) experimentally depressed college students performed unannounced tests of free recall following learning tasks with two levels of difficulty and (in Experiment 2) two degrees of structure. In Experiments 1 and 2 we measured cognitive effort on those tasks via latencies on a secondary task. Latencies and subsequent recall increased with the structure and difficulty of the learning task for nondepressed and naturally depressed subjects, but these effects were reduced or absent for experimentally depressed subjects. When the secondary task was omitted (Experiment 3), naturally depressed students still recalled without a deficit. We discuss possible differences associated with the two types of depression and implications for the cognitive-effort account.The order of authorship was determined alphabetically. This project was supported by grant R03 MH44044 from the National Institute of Mental Health and by a Trinity University Summer Stipend, each granted to the first author. Portions of the data in Experiment 2 were collected by Scott Schoenherr for his Senior Thesis at Trinity University. We thank Patti Boulanger, Anne-Marie DeWitt, Roger Foster, Tracey Hatcher, Lara Hill, Meg Johnson, and Dottie Masturzo for their assistance in scheduling, scoring, and data collection. We thank Tom Hicks and Pat Kyllonen (especially) for programming efforts. Gil Einstein, Henry Ellis, Rick Ingram, and Colin MacLeod provided helpful comments on an earlier version of the article.     

Cholinergic neuronal lesions in the medial septum and vertical limb of the diagonal bands of Broca induce contextual fear memory generalization and impair acquisition of fear extinction

Previous research has shown that the ventral medial prefrontal cortex (vmPFC) and hippocampus (Hipp) are critical for extinction memory. Basal forebrain (BF) cholinergic input to the vmPFC and Hipp is critical for neural function in these substrates, which suggests BF cholinergic neurons may be critical for extinction memory. In order to test this hypothesis, we applied cholinergic lesions to different regions of the BF and observed the effects these lesions had on extinction memory. Complete BF cholinergic lesions induced contextual fear memory generalization, and this generalized fear was resistant to extinction. Animals with complete BF cholinergic lesions could not acquire cued fear extinction. Restricted cholinergic lesions in the medial septum and vertical diagonal bands of Broca (MS/vDBB) mimicked the effects that BF cholinergic lesions had on contextual fear memory generalization and acquisition of fear extinction. Cholinergic lesions in the horizontal diagonal band of Broca and nucleus basalis (hDBB/NBM) induced a small deficit in extinction of generalized contextual fear memory with no accompanying deficits in cued fear extinction. The results of this study reveal that MS/vDBB cholinergic neurons are critical for inhibition and extinction of generalized contextual fear memory, and via this process, may be critical for acquisition of cued fear extinction. Further studies delineating neural circuits and mechanisms through which MS/vDBB cholinergic neurons facilitate these emotional memory processes are needed. © 2015 Wiley Periodicals, Inc.     

Dopaminergic system and dream recall: An MRI study in Parkinson's disease patients

We investigated the role of the dopamine system [i.e., subcortical‐medial prefrontal cortex (mPFC) network] in dreaming, by studying patients with Parkinson's Disease (PD) as a model of altered dopaminergic transmission. Subcortical volumes and cortical thickness were extracted by 3T‐MR images of 27 PD patients and 27 age‐matched controls, who were asked to fill out a dream diary upon morning awakening for one week. PD patients do not substantially differ from healthy controls with respect to the sleep, dream, and neuroanatomical measures. Multivariate correlational analyses in PD patients show that dopamine agonist dosage is associated to qualitatively impoverished dreams, as expressed by lower bizarreness and lower emotional load values. Visual vividness (VV) of their dream reports positively correlates with volumes of both the amygdalae and with thickness of the left mPFC. Emotional load also positively correlates with hippocampal volume. Beside the replication of our previous finding on the role of subcortical nuclei in dreaming experience of healthy subjects, this represents the first evidence of a specific role of the amygdala‐mPFC dopaminergic network system in dream recall. The association in PD patients between higher dopamine agonist dosages and impoverished dream reports, however, and the significant correlations between VV and mesolimbic regions, however, provide an empirical support to the hypothesis that a dopamine network plays a key role in dream generation. The causal relation is however precluded by the intrinsic limitation of assuming the dopamine agonist dosage as a measure of the hypodopaminergic state in PD. Hum Brain Mapp 37:1136–1147, 2016. © 2015 Wiley Periodicals, Inc .     

Diet Quality and Fruit,Vegetable, and Sugar-Sweetened Beverage Consumption by Household Food Insecurity among 8- to 12-Year-Old Children during Summer Months

BackgroundSchool-delivered nutrition assistance programs have improved dietary intake for children from food-insecure households during the school year. However, little is known about their diet quality and eating patterns during summer months.ObjectiveSchool-aged children’s summer month weekday and weekend day diet quality and eating patterns were assessed by household food insecurity.DesignSecondary analysis of cross-sectional data was employed.Participants/settingDuring the summers of 2011 through 2017, baseline data were collected from parent–child dyads participating in one of two community-based obesity prevention trials in metropolitan Minnesota (N=218). The mean age of children was 10 years; 50% were girls, 49% were nonwhite, and 25% were from food-insecure households.Main outcome measuresChildren from food-secure and food-insecure households were identified by using the short form of the US Household Food Security Survey. Healthy Eating Index 2015 and eating patterns—including energy intake and consumption of whole fruits, vegetables, 100% fruit/vegetable juice, and sugar-sweetened beverages—were estimated by means of 24-hour dietary recall interviews conducted on weekdays and weekend days.Statistical analysis performedGeneral linear modeling was used to examine diet quality and eating patterns by food insecurity, controlling for child age, child body mass index z score, and parent education.ResultsChildren from food-insecure and food-secure households had Healthy Eating Index 2015 scores less than 50. Children from food-insecure households reported less energy intake, fewer cups of whole fruit, and more sugar-sweetened beverage consumption for every 1,000 kcal consumed on a weekend day when compared with their counterparts from food-secure households (P<0.05). Similar results were not seen for weekday eating patterns.ConclusionsWhole fruit and sugar-sweetened beverage consumption varied by food insecurity on weekend days during summer months. Because children tend to gain weight during summer months, efforts to increase weekend access to whole fruits and promote water consumption may contribute to weight gain prevention and healthy development, especially for children from food-insecure households.